scholarly journals The structure of Artemia sp. (brine shrimp) haemoglobins. Purification of a structural unit to homogeneity

1985 ◽  
Vol 227 (3) ◽  
pp. 917-924 ◽  
Author(s):  
L Moens ◽  
M L Van Hauwaert ◽  
G Wolf
Keyword(s):  
Brine Shrimp ◽  
Structural Unit ◽  
Single Type ◽  
Structural Units ◽  
Limited Digestion

The extracellular haemoglobins (Mr 260 000) of the brine shrimp Artemia sp. were cleaved by limited digestion with subtilisin. Structural units of Mr 16 000, which can bind dioxygen reversibly, were isolated. Analysis of the 16 000-Mr fraction (E) reveals the presence of a limited number of structural units. A single type of structural unit, E1 (Mr 15 800; pI4.8), was purified to homogeneity and characterized.

Structural variation in wollastonite and bustamite

1985 ◽  
Vol 49 (350) ◽  
pp. 37-48 ◽  
Author(s):  
R. J. Angel
Keyword(s):  
Structural Unit ◽  
Structural Variation ◽  
Relative Displacement ◽  
Single Type ◽  
Stacking Sequence ◽  
Structural Units ◽  
Ordered Structures ◽  
Unit Cells ◽  
Line Defects

AbstractThe structures of bustamite and the poly-types of wollastonite are shown to be derived from variations in the stacking sequence of a single type of structural unit. This structural unit is a column of unit cells of wollastonite along the b-axis and is bounded by (100) and (001) planes (P1̄ cell); these units may be stacked together along [100] and [001] with either zero displacement between successive units, or a relative displacement of 1/2[010]. Regular stacking sequences give rise to the ordered structures of wollastonite polytypes and of bustamite, while the transformations between these structures proceed by the propagation of line defects with Burgers vectors of 1/2[010] which thus change the stacking sequence of the structural units.

scholarly journals Formation of integrated structural units using the systematic and integrated method when implementing high-rise construction projects

2018 ◽  
Vol 33 ◽  
pp. 03075 ◽  
Author(s):  
Ivan Abramov
Keyword(s):  
Construction Projects ◽  
Structural Unit ◽  
System Analysis ◽  
Research Priorities ◽  
Structural Units ◽  
Factors Affecting ◽  
Reliability Criterion ◽  
Integrated Method ◽  
Destabilizing Factors ◽  
The Impact

Development of design documentation for a future construction project gives rise to a number of issues with the main one being selection of manpower for structural units of the project’s overall implementation system. Well planned and competently staffed integrated structural construction units will help achieve a high level of reliability and labor productivity and avoid negative (extraordinary) situations during the construction period eventually ensuring improved project performance. Research priorities include the development of theoretical recommendations for enhancing reliability of a structural unit staffed as an integrated construction crew. The author focuses on identification of destabilizing factors affecting formation of an integrated construction crew; assessment of these destabilizing factors; based on the developed mathematical model, highlighting the impact of these factors on the integration criterion with subsequent identification of an efficiency and reliability criterion for the structural unit in general. The purpose of this article is to develop theoretical recommendations and scientific and methodological provisions of an organizational and technological nature in order to identify a reliability criterion for a structural unit based on manpower integration and productivity criteria. With this purpose in mind, complex scientific tasks have been defined requiring special research, development of corresponding provisions and recommendations based on the system analysis findings presented herein.

scholarly journals RELATIVE DISTANCE: THE KEY TO THE SHAPE OF HEPATIC BUILDING BLOCKS

2011 ◽  
Vol 19 (1) ◽  
pp. 19 ◽  
Author(s):  
Jan M Ruijter ◽  
Marry M Markman ◽  
Jaco Hagoort ◽  
Antoon FM Moorman ◽  
Wouter H Lamers
Keyword(s):  
Portal Vein ◽  
Mouse Liver ◽  
Structural Unit ◽  
Building Blocks ◽  
Relative Volume ◽  
Central Vein ◽  
Terminal Branch ◽  
Relative Area ◽  
Structural Units ◽  
Relative Radius

The delineation and the shape of the smallest structural units of the liver is still the subject of debate. However,the blood flow from an upstream terminal branch of the portal vein to a downstream central vein is thought to induce a functional zonation in hepatocyte gene expression. This property was used to determine boundary conditions for the shape of the hepatic building blocks. Histochemical techniques that specifically label periportally or pericentrally expressed enzymes can be used to distinguish periportal and pericentral areas in a liver section. Pairs of images from aligned serial sections, one stained for a portal and the next for a central enzyme, are used. Segmentation and skeletonisation of these images results in the skeletons of the portal and central areas. Distance transformation with respect to these skeletons gives for each point in the image pair the distance to the nearest terminal branches of the portal vein and the central vein. For each point the relative position on the porto-central radius can then be calculated as its distance to a portal vein divided by the sum of its portal and its central distance. In the resulting relative radius image, the area occupied by 'zones' of equivalent relative radius can be measured. According to the principle of Delesse the relative area of a zone in the image is equal to the relative volume of that zone in the tissue. For structural units of plate-like, cylindrical or spherical shape, the relative volume of a zone is equal to the relative radius of that zone to the power 1, 2 or 3, respectively. Thus, the exponent in the relative area - relative radius relation gives information on the shape of the structural unit. Measurement of the areas of each relative radius zone and determination of the area - radius relation in images of random sections of adult mouse liver results in an exponent of 1.1. This suggests that the smallest structural unit of the mouse liver has the shape of a needle.

The structure of a near Σ=27 tilt grain boundary in Ge

1992 ◽  
Vol 50 (1) ◽  
pp. 214-215
Author(s):  
Stuart McKernan ◽  
C. Barry Carter
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Structural Unit ◽  
Perfect Crystal ◽  
Boundary Plane ◽  
Boundary Structure ◽  
Structural Units ◽  
Grain Boundary Plane ◽  
Grain Boundary Structure ◽  
Complex Structural

The modeling of tilt grain boundaries in terms of repeating structural units of varying separation is now a well established concept. High-resolution electron microscope (HREM) images of different tilt grain boundaries in many materials display a qualitative similarity of atomic configurations of the grain boundary structure. These boundaries are frequently described in terms of characteristic structural units, which may be separated from each other by regions of ‘perfect’ crystal (as, for example, in low-angle grain boundaries), or may be contiguous, forming ordered arrays of the structural units along the boundary. In general there will be a different arrangement of the structural units or an arrangement of different structural units, according to the precise geometry of the particular grain boundary. The structure of some special grain boundaries has been examined and these are found to exist in several different configurations, depending on the orientation of the grain boundary plane among other parameters. Symmetry-related symmetric tilt grain boundaries and asymmetric tilt grain boundaries with one grain having a prominent, low-index facet, are commonly observed, low-energy configurations. Structural multiplicity of these configurations along the same grain boundary has been observed in some systems. Defects in the perfect ordering of the structural units may be caused by deviations of the grain boundary plane away from the perfect tilt orientation. Deviations of grain boundary structure away from the exact orientation will also produce defects in the repeating structural unit configuration. These deviations may have a regular and well-defined structure, producing a more complex structural unit.

Bias deployable grids with horizontal compound scissor-like elements: A geometric study of the folding/deployment process

2021 ◽  
pp. 095605992110640
Author(s):  
Manuel J Freire-Tellado ◽  
Manuel Muñoz-Vidal ◽  
Juan Pérez-Valcárcel
Keyword(s):  
Structural Unit ◽  
Kinematic Model ◽  
Three Dimensional ◽  
Angular Distortion ◽  
Structural Units ◽  
Load Bearing ◽  
Stable Structures ◽  
Geometric Study

Bias deployable structural units are two-way structures arranged in a rotational pattern with respect to the edges. They have interesting advantages such as robust three-dimensional operation with supports around their entire base perimeter and the exclusive use of load-bearing scissor-like elements (SLEs). However, they do not have edge trims and their resistance to angular distortion is limited. This article proposes a series of deployable bi-stable structures that address these problems and incorporate new, resilient features. A method of analysing the incompatibilities of the structural unit is developed based solely on the geometric study of the deployment process, which allows the level of incompatibility of the proposal to be graduated, varying from stress-free structures to bi-stable structures. A kinematic model of one of the proposals allows the research undertaken to be contrasted.

Experimental and numerical studies on the deployment process of self-locking cuboid foldable structural units

2020 ◽  
Vol 23 (16) ◽  
pp. 3496-3508 ◽  
Author(s):  
Zhanwei Zhao ◽  
Weibing Hu ◽  
Lei Yu
Keyword(s):  
Structural Unit ◽  
Numerical Models ◽  
Theoretical Models ◽  
The Self ◽  
Structural Performance ◽  
Bending Moments ◽  
Structural Units ◽  
Large Rotation ◽  
Numerical Studies ◽  
Spatial Configurations

Structural units are the basic components of self-locking foldable grid structures, and their spatial configurations have a vital influence on the structural performance of the overall grid. Research on the deployment process of structural units can help effectively control their stress level and achieve a rational self-locking capability for the units. Therefore, this article describes experimental and modeling studies on the deployment process of structural units and provides a reference for the establishment of numerical models and the design of structural units. The experimental results revealed that the self-locking capability of a structural unit is mainly determined by the bending moments of its members in the planes of the scissor-like elements. The method for adjusting the locations of the pivot endpoints at the radial bars is effective for improving the self-locking capacity, but the degree of adjustment must be strictly controlled to prevent large rotation at the inner lower hub joint. In addition, the feasibility of the modeling method was verified by comparing the experimental curves with the curves obtained by theoretical models.

scholarly journals STRENGTH ANALYSIS OF SCREW CONVEYOR DRIVE

2021 ◽  
Vol 2021 (6) ◽  
pp. 5488-5491
Author(s):  
TOMAS CORANIC ◽  
◽  
JOZEF MASCENIK ◽  
Keyword(s):  
Structural Unit ◽  
Strength Characteristics ◽  
Screw Conveyor ◽  
Strength Analysis ◽  
Structural Units ◽  
Theoretical Part ◽  
Theoretical Assumptions ◽  
Manufacturing Engineering ◽  
The Given ◽  
Manufacturing Machine

The present paper deals with research of strength characteristics in manufacturing engineering. The introduction of the work describes findings about the importance of the given subject. The publication is divided into two basic parts, namely the theoretical and the practical part. The theoretical part provides a detailed description of theoretical assumptions on solutions in the field of research, and it also describes optimization of structural units in manufacturing engineering, while the practical part analyses strength characteristics of the selected structural unit which is the drive of a manufacturing machine. The conclusion of the work presents the obtained results.

scholarly journals Questioning the clause as a crosslinguistic unit in grammar and interaction

2019 ◽  
Vol 43 (2) ◽  
pp. 364-401 ◽  
Author(s):  
Ritva Laury ◽  
Tsuyoshi Ono ◽  
Ryoko Suzuki
Keyword(s):  
Qualitative Analysis ◽  
Structural Unit ◽  
Structural Units ◽  
Theoretical Status ◽  
Everyday Talk ◽  
Grammar And Interaction

Abstract This paper focuses on ‘clause’, a celebrated structural unit in linguistics, by comparing Finnish and Japanese, two languages which are genetically, typologically, and areally distinct from each other and from English, the language on the basis of which this structural unit has been most typically discussed. We first examine how structural units including the clause have been discussed in the literature on Finnish and Japanese. We will then examine the reality of the clause in everyday talk in these languages quantitatively and qualitatively; in our qualitative analysis, we focus in particular on what units are oriented to by conversational participants. The current study suggests that the degree of grammaticization of the clause varies cross-linguistically and questions the central theoretical status accorded to this structural unit.

Alkaline hydrolysis of pivalic esters of ethylene glycol in water-acetone solutions

1980 ◽  
Vol 45 (3) ◽  
pp. 720-726 ◽  
Author(s):  
Stanislav Ševčík ◽  
Miroslav Kubín ◽  
Jiří Štamberg
Keyword(s):  
Ethylene Glycol ◽  
Alkaline Hydrolysis ◽  
Structural Unit ◽  
Hydroxyethyl Methacrylate ◽  
Structural Units ◽  
Kinetics Of Hydrolysis ◽  
Ethylene Dimethacrylate ◽  
Crosslinking Site ◽  
Kinetics Of ◽  
Hydrolysis Of

The paper reports alkaline hydrolysis of ethylene dipivalate and 2-hydroxyethyl pivalates as compounds modelling the structural unit and crosslinking site of hydrophilic gels, i.e. copolymers of 2-hydroxyethyl methacrylate and ethylene dimethacrylate. The kinetics of hydrolysis was investigated in water-acetone solutions containing respectively 50, 75, 80, 85 and 90% by vol. (related to 20°C) of acetone at 20, 30, 40, and 50°C. It was demonstrated that, owing to steric hindrance, the preferential hydrolysis of monoester was more pronounced in the case of pivalic esters of ethylene glycol compared with acetic esters of ethylene glycol. The results are discussed in connection with the selectivity of the alkaline hydrolysis of ester bonds in "pendant" parts of structural units in hydrophylic methacrylate gels.

New Efficient and Accurate Method of Nonlinear Analysis of Offshore Tubular Frames (the Idealized Structural Unit Method)

1985 ◽  
Vol 107 (2) ◽  
pp. 204-211 ◽  
Author(s):  
Y. Ueda ◽  
S. M. H. Rashed ◽  
K. Nakacho
Keyword(s):  
Residual Stresses ◽  
Nonlinear Analysis ◽  
Structural Unit ◽  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Accurate Method ◽  
Large Deflections ◽  
Structural Units ◽  
High Degree

The Idealized Structural Unit Method [1, 2] is applied to the analysis of nonlinear behavior of three-dimensional offshore tubular frames. To this purpose the “tubular structural unit” is developed and used to analyze the entire behavior of the frame until final collapse. In this method large deflections, instability, plasticity and the effect of residual stresses and initial out of straightness are considered. Modeling of a structure is very simple since large structural units are regarded as elements. The required computer effort is very small while attaining a high degree of accuracy and reliability.

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