scholarly journals Relationships among xylem transport, anatomical structure and mechanical strength in stems and roots of three Podocarpaceae species

2021 ◽  
Vol 45 (6) ◽  
pp. 659-669
Author(s):  
Shi-Tong LU ◽  
Sen CHEN ◽  
Yan LI ◽  
Zhong-Yuan WANG ◽  
Tian-Tian PAN ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Anatomical Structure ◽  
Xylem Transport

scholarly journals Conifer tracheids resolve conflicting structural requirements: Data, hypotheses, questions

2017 ◽  
Vol 11 (1) ◽  
pp. 123-141
Author(s):  
Sherwin Carlquist
Keyword(s):  
Mechanical Strength ◽  
Cell Walls ◽  
Surface Relief ◽  
Anatomical Structure ◽  
Structural Requirements ◽  
Wall Strength ◽  
Pit Membrane ◽  
Bordered Pits ◽  
Cool Temperate ◽  
Solid Cell

The nature of conduction involves movement of a liquid (under tension or pressure) through a solid (cell walls necessary to direct the liquid and provide mechanical strength). The numerous consequences of the liquid/solid nature of the conductive interface in plants can be viewed as a series of conflicting requirements that are resolved by various mechanisms. For example, the types of mechanical strength conferred by thicker cell walls (latewood) run counter to optimal conduction (earlywood). Conflict resolution situations are examined with light microscopy and SEM to show in detail not merely conflicting requirements but the various types of resolution in various conifers. Abies is presented as exemplary of a cool temperate conifer with numerous aspects to earlywood/latewood structure. Tropical conifers (Araucaria) present different compromises; the riparian conifer Dacrydium guillauminii has only earlywood; the parasitic conifer Parasitaxus has only latewood. Particular conifers have only some of the features by which latewood differs from earlywood. Cell dimorphism is only one aspect of resolution of conflicting requirements; others include modifications in pit size, shape, and density; the nature of the pit membrane; the nature of the pit cavity, pit border and pit aperture; and surface relief (warty layer) of the tracheid wall. The invention of coniferous bordered pits involves a circular shape, so that tension on the margo strands is equal, and thus the pit can be closed. These factors and margo pore maximization necessitate expending a large amount of space to pits in earlywood, the strength of which is thereby lessened and must be compensated by greater wall strength in latewood. The paper concludes with a series of twenty features which represent resolutions of conflicting requirements in terms of anatomical structure. Wood physiological literature is integrated with the anatomical observations.

scholarly journals SURGICAL TREATMENT OF DISTROPHICAL BONE KISTS BY TITANIUM NIKELID POROUS MATERIALS IN CHILDREN

2015 ◽  
Vol 14 (2) ◽  
pp. 42-46
Author(s):  
G. V. Slizovskiy ◽  
L. A. Sitko ◽  
I. I. Kuzhelivskiy
Keyword(s):  
Surgical Treatment ◽  
Mechanical Strength ◽  
Porous Materials ◽  
Standard Treatment ◽  
High Efficiency ◽  
Anatomical Structure ◽  
Treatment Technology ◽  
Technology Group ◽  
Comparative Examination

The article presents the results of bone kists treatment by porous granular titanium nikelid materials. A comparative examination with standard treatment technology group demonstrated high efficiency of a proposed method. Porous granular titanium nikelid materials possess mechanical strength, optimization of regeneration  at the expense of osteoinductivity and  allow you  to  effectively fill the cavity with a complex anatomical structure.

scholarly journals ARCHITECTONICS OF PLANTS IN ASPECT OF FORMATION OF NATURE-LIKE OBJECTS

2019 ◽  
Vol 9 (4) ◽  
pp. 82-90
Author(s):  
Dmitry V. KARELIN ◽  
Yulia E. CHMIR
Keyword(s):  
Mechanical Strength ◽  
Construction Industry ◽  
Biological Systems ◽  
Relative Volume ◽  
Anatomical Structure ◽  
Living Systems ◽  
Practical Orientation ◽  
Grain Crops ◽  
Experimental Part ◽  
Highly Effective

The great interest of modern scientifi c society in architectural bionics is due to the signifi cant practical orientation of this science, which studies the principles of construction and functioning of biological systems, primarily with the aim of creating new bionic objects whose characteristics would be as perfect and highly effective as in living systems. Architectural-bionic practice gave rise to unusual forms, suitable in a functional and utilitarian sense. The architectural bionics family can off er a lot of cereals, which have the property of elasticity and resistance to bending and fracture with a few materials. In wheat, as in a number of other grain crops, the strength of the stem is determined by a set of features of the anatomical structure. The structure of the article reveals the concept of sustainable architecture, referring to antiquity. The basis of the study is a bionic object displayed in the form of a stalk of wheat, the properties of which allow wheat to undergo atmospheric infl uences under the existing load of ears, which greatly exceeds the own weight of the straw. The properties of the elasticity of the stem of the wheat are examined through the Young’s modulus (E), which provides resistance to lodging. In the experimental part, an explanation is given of the mechanical strength of the wheat stalk, characteristic of most cereals, due to: height, diameter of the stem, their ratio, the thickness of the walls of the straw, the development of mechanical tissues. For an illustrative example, the predominant properties of the stalk of wheat, the calculations of the relative volume using standard materials in the construction industry of uplifting buildings and structures are given.

Re-evaluation of the role of ureides in the xylem transport of nitrogen in Arachis species

1991 ◽  
Vol 83 (4) ◽  
pp. 560-567 ◽  
Author(s):  
M. B. Peoples ◽  
C. A. Atkins ◽  
J. S. Pate ◽  
K. Chong ◽  
A. W. Faizah ◽  
...  
Keyword(s):  
Arachis Species ◽  
Xylem Transport

FORMULATION AND DEVELOPMENT OF FAST DISSOLVING TABLET OF METOCLOPRAMIDE: AN ANTI-EMETIC DRUG

2019 ◽  
Vol 8 (6) ◽  
Author(s):  
Avilash Carpenter ◽  
M.K. Gupta ◽  
Neetesh Kumar Jain ◽  
Urvashi Sharma ◽  
Rahul Sisodiya
Keyword(s):  
Mechanical Strength ◽  
Standard Procedure ◽  
Flow Property ◽  
Storage Conditions ◽  
Angle Of Repose ◽  
Dissolution Time ◽  
Disintegration Time ◽  
Powder Blend ◽  
Standard Curve ◽  
The Stability

Aim: The main of the study is to formulate and develop orally disintegrating fast dissolving tablet of Metoclopramide hydrochloride. Material & Methods: Before formulation and development of selected drug, the standard curve in buffer was prepared and absorbance at selected maxima was taken. Then two different disintegrating agents were selected and drug was mixed with disintegrating agents in different ratio. Various Preformulation parameters and evaluation of tablet i.e. disintegration time, dissolution time, friability, hardness, thickness were measured by standard procedure. Result & Discussion: The angle of repose for all the batches prepared. The values were found to be in the range of 30.46 to 36.45, which indicates good flow property for the powder blend according to the USP. The bulk density and tapped density for all the batches varied from 0.49 to 0.54 g/mL and 0.66 to 0.73, respectively. Carr’s index values were found to be in the range of 23.33 to 25.88, which is satisfactory for the powders as well as implies that the blends have good compressibility. Hausner ratio values obtained were in the range of 1.22 to 1.36, which shows a passable flow property for the powder blend based on the USP. The results for tablet thickness and height for all batches was found to range from 4.45 to 4.72 mm and 3.67 to 3.69 mm, respectively. Hardness or breaking force of tablets for all batches was found to range from 32.8 to 36.2 N. Tablet formulations must show good mechanical strength with sufficient hardness in order to handle shipping and transportation. Friability values for all the formulations were found to be in the range of 0.22 % to 0.30 %. Conclusion: Orally disintegrating tablets were compressed in order to have sufficient mechanical strength and integrity to withstand handling, shipping and transportation. The formulation was shown to have a rapid disintegration time that complied with the USP (less than one minute). The data obtained from the stability studies indicated that the orally disintegrating mini-tablets of MTH were stable under different environmental storage conditions. Keywords: Formulation & Development, Fast Dissolving Tablet, Metoclopramide, Anti-Emetic Drug, Oral Disintegrating Tablet

Plasma Enhanced Chemical Vapor Deposition of Porous Organosilicate Glass ILD Films With k ≤ 2.4.

2003 ◽  
Vol 766 ◽  
Author(s):  
Raymond N. Vrtis ◽  
Mark L. O'Neill ◽  
Jean L. Vincent ◽  
Aaron S. Lukas ◽  
Brian K. Peterson ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Chemical Vapor Deposition ◽  
Mechanical Strength ◽  
Thermal Annealing ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organosilicate Glass

AbstractWe report on our work to develop a process for depositing nanoporous organosilicate (OSG) films via plasma enhanced chemical vapor deposition (PECVD). This approach entails codepositing an OSG material with a plasma polymerizable hydrocarbon, followed by thermal annealing of the material to remove the porogen, leaving an OSG matrix with nano-sized voids. The dielectric constant of the final film is controlled by varying the ratio of porogen precursor to OSG precursor in the delivery gas. Because of the need to maintain the mechanical strength of the final material, diethoxymethylsilane (DEMS) is utilized as the OSG precursor. Utilizing this route we are able to deposit films with a dielectric constant of 2.55 to 2.20 and hardness of 0.7 to 0.3 GPa, respectively.

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