Shell morphology, shell texture and species discrimination of Caribbean Tucetona (Bivalvia, Glycymeridae)

2001 ◽  
Vol 75 (5) ◽  
pp. 658-679 ◽  
Author(s):  
Pascal E. Tschudin
Keyword(s):  
Structural Features ◽  
Shell Morphology ◽  
Species Discrimination ◽  
Cross Sectional ◽  
Consistent System ◽  
Diagnostic Characters ◽  
Hinge Plate ◽  
Lamellar Texture ◽  
The One ◽  
Sectional Shape

Previous descriptions of Tucetona lack a consistent system using diagnostic characters and only two recent Caribbean ‘species' are recognized. In this study, textural and structural features of the Tucetona shell are examined and used as the basis for comparison to other glycymerids and in the recognition of morphospecies. Standard diagnostic characters based mainly on the cross-sectional shape of ribs and on hinge teeth ontogeny are presented and used to distinguish six recent Caribbean morphospecies. The shell texture has been examined by light and scanning electron microscopy, showing the interior of glycymerid hinge teeth structured by two bundles of crossed lamellar texture. Whereas European Glycymeris examined for comparison correspond in their hinge plate textures to the one found in Tucetona, differences from a Caribbean Glycymeris sp. are described. Simple lamellar, crossed-lamellar and cone complex crossed-lamellar textures showed the same basic crystallite subunits.

Shell morphology, shell texture and species discrimination of Caribbean Tucetona (Bivalvia, Glycymeridae)

2001 ◽  
Vol 75 (3) ◽  
pp. 658-679 ◽  
Author(s):  
Pascal E. Tschudin
Keyword(s):  
Structural Features ◽  
Shell Morphology ◽  
Species Discrimination ◽  
Cross Sectional ◽  
Consistent System ◽  
Diagnostic Characters ◽  
Hinge Plate ◽  
Lamellar Texture ◽  
The One ◽  
Sectional Shape

Previous descriptions of Tucetona lack a consistent system using diagnostic characters and only two recent Caribbean ‘species’ are recognized. In this study, textural and structural features of the Tucetona shell are examined and used as the basis for comparison to other glycymerids and in the recognition of morphospecies. Standard diagnostic characters based mainly on the cross-sectional shape of ribs and on hinge teeth ontogeny are presented and used to distinguish six recent Caribbean morphospecies. The shell texture has been examined by light and scanning electron microscopy, showing the interior of glycymerid hinge teeth structured by two bundles of crossed lamellar texture. Whereas European Glycymeris examined for comparison correspond in their hinge plate textures to the one found in Tucetona, differences from a Caribbean Glycymeris sp. are described. Simple lamellar, crossed-lamellar and cone complex crossed-lamellar textures showed the same basic crystallite subunits.

scholarly journals Some Investigations on the Anisotropy of the Chemical Etching of (hk0) and (hhl) Silicon Plates in a NaOH 35% Solution. Part I: 2D Etching Shapes

2001 ◽  
Vol 24 (1) ◽  
pp. 31-56 ◽  
Author(s):  
C. A. Hodebourg ◽  
C. R. Tellier
Keyword(s):  
Chemical Etching ◽  
Practical Interest ◽  
Circular Plates ◽  
Cross Sectional ◽  
Geometrical Features ◽  
Analysis Of Results ◽  
Surface Profiles ◽  
The One ◽  
Sectional Shape ◽  
Dissolution Slowness

In this paper a study of the anisotropic dissolution of (hk0) and (hhl) silicon plates in a NaOH 35% solution is undertaken. Effects of orientation on firstly, the geometrical features of etched surfaces and secondly, on the cross-sectional shape of starting circular plates are systematically investigated. Conclusions of practical interest on the roughness of etched (hk0) and (hhl) planes are drawn. 2D etching shapes are then analysed in terms of the tensorial model for the anisotropic dissolution and of dissolution criteria. Finally a comparative analysis of results related on the one hand, to 2D surface profiles and on the other, to out-of-roundness profiles is made. This comparison shows that shapes observed for profilometry traces agree with theoretical shapes as derived when we use the resemblance in shapes between out-of-roundness profiles and polar diagrams of the dissolution slowness.

On the cross-sectional shape of the cellulose crystallites in the tunicate Halocynthia papillosa

1990 ◽  
Vol 48 (3) ◽  
pp. 566-567
Author(s):  
J.-F. Revol ◽  
Y. Van Daele ◽  
F. Gaill
Keyword(s):  
Contrast Imaging ◽  
Animal Kingdom ◽  
Bright Field ◽  
Field Mode ◽  
Cross Sectional ◽  
Ultrathin Sections ◽  
The Cross ◽  
Sectional Shape ◽  
Valonia Ventricosa ◽  
C Nmr

The only form of cellulose which could unequivocally be ascribed to the animal kingdom is the tunicin that occurs in the tests of the tunicates. Recently, high-resolution solid-state l3C NMR revealed that tunicin belongs to the Iβ form of cellulose as opposed to the Iα form found in Valonia and bacterial celluloses. The high perfection of the tunicin crystallites led us to study its crosssectional shape and to compare it with the shape of those in Valonia ventricosa (V.v.), the goal being to relate the cross-section of cellulose crystallites with the two allomorphs Iα and Iβ.In the present work the source of tunicin was the test of the ascidian Halocvnthia papillosa (H.p.). Diffraction contrast imaging in the bright field mode was applied on ultrathin sections of the V.v. cell wall and H.p. test with cellulose crystallites perpendicular to the plane of the sections. The electron microscope, a Philips 400T, was operated at 120 kV in a low intensity beam condition.

Internalizing Behavior During the Transition from Childhood to Adolescence

2010 ◽  
Vol 26 (3) ◽  
pp. 187-193 ◽  
Author(s):  
Marc Vierhaus ◽  
Arnold Lohaus ◽  
Indra Shah
Keyword(s):  
Research Design ◽  
Internalizing Symptoms ◽  
Fourth Graders ◽  
Cross Sectional Study ◽  
Second Graders ◽  
Internalizing Behavior ◽  
Longitudinal Assessment ◽  
Sectional Study ◽  
Cross Sectional ◽  
The One

This investigation focuses on the question whether assessments of the development of internalizing behavior from childhood to adolescence are affected by the kind of research design (longitudinal versus cross-sectional). Two longitudinal samples of 432 second-graders and 366 fourth graders participated in a longitudinal study with subsequent measurements taken 1, 2, and 3 years later. A third sample consisting of 849 children covering the same range of grades participated in a cross-sectional study. The results show that the development of internalizing symptoms in girls – but not in boys – varies systematically with the research design. In girls, there is a decrease of internalizing symptoms (especially between the first two timepoints) in the longitudinal assessment, which may reflect, for example, the influence of strain during the first testing situation. Both longitudinal trajectories converge to a common trajectory from grade 2 to grade 7 when controlling for this “novelty-distress effect.” Moreover, when we control this effect, the slight but significant decrease characterizing the common trajectory becomes similar to the one obtained in the cross-sectional study. Therefore, trajectories based on longitudinal assessments may suggest more changes with regard to internalizing symptoms over time than actually take place, while trajectories based on cross-sectional data may be characterized by an increased level of internalizing symptoms. Theoretical and practical implications of these results are discussed.

Effect of Varied Probe Length on the Resonant Frequency of a Circular Cross-Sectional Cavity

2005 ◽  
Vol 2 (2) ◽  
pp. 79
Author(s):  
Mohd Khairul Mohd Salleh ◽  
Mohamad Syukri Suhaili ◽  
Zuhani Ismail ◽  
Zaiki Awang
Keyword(s):  
Resonant Frequency ◽  
Cavity Resonator ◽  
Simple Design ◽  
Cross Sectional ◽  
Probe Length ◽  
Mode Wave ◽  
The One

A simple design of a metallic circular cross-sectional air-filled cavity is presented. Two probes of varied lengths are used to excite TE112-mode wave into the cavity to give a resonant frequency of 5.86 GHz. The experiments show that the resonant frequency of the cavity resonator decreases as the lengths of the probes are increased. The shortest probe in the range of study gives the closest resonant frequency to the one desired.

Failure Analysis Due to Slightly Unetched Hard Mask Using Nano Probe

2013 ◽  
Author(s):  
Jong Hak Lee ◽  
Jong Eun Kim ◽  
Chang Su Park ◽  
Nam Il Kim ◽  
Jang Won Moon ◽  
...  
Keyword(s):  
Leakage Current ◽  
Circuit Simulation ◽  
The State ◽  
Physical Analysis ◽  
Cross Sectional ◽  
Hard Mask ◽  
Current Flows ◽  
Voltage Contrast ◽  
The One ◽  
Zero Voltage

Abstract In this work, a slightly unetched gate hard mask failure was analyzed by nano probing. Although unetched hard mask failures are commonly detected from the cross sectional view with FIB or FIB-TEM and planar view with the voltage contrast, in this case of the very slightly unetched hard mask, it was difficult to find the defects within the failed area by physical analysis methods. FIB is useful due to its function of milling and checking from the one region to another region within the suspected area, but the defect, located under contact was very tiny. So, it could not be detected in the tilted-view of the FIB. However, the state of the failure could be understood from the electrical analysis using a nano probe due to its ability to probe contact nodes across the fail area. Among the transistors in the fail area, one transistor’s characteristics showed higher leakage current and lower ON current than expected. After physical analysis, slightly remained hard mask was detected by TEM. Chemical processing was followed to determine the gate electrode (WSi2) connection to tungsten contact. It was also proven that when gate is floated, more leakage current flows compared to the state that the zero voltage is applied to the gate. This was not verified by circuit simulation due to the floating nodes.

Automated 3D measurement of fiber cross section morphology in handsheets

2012 ◽  
Vol 27 (2) ◽  
pp. 264-269 ◽  
Author(s):  
Christian Lorbach ◽  
Ulrich Hirn ◽  
Johannes Kritzinger ◽  
Wolfgang Bauer
Keyword(s):  
Image Analysis ◽  
Cross Section ◽  
Cross Sections ◽  
Image Plane ◽  
3D Measurement ◽  
Cross Sectional ◽  
Fiber Cross Section ◽  
Fiber Wall ◽  
Sectional Shape ◽  
Cross Section Geometry

Abstract We present a method for 3D measurement of fiber cross sectional morphology from handsheets. An automated procedure is used to acquire 3D datasets of fiber cross sectional images using an automated microtome and light microscopy. The fiber cross section geometry is extracted using digital image analysis. Simple sample preparation and highly automated image acquisition and image analysis are providing an efficient tool to analyze large samples. It is demonstrated that if fibers are tilted towards the image plane the images of fiber cross sections are always larger than the true fiber cross section geometry. In our analysis the tilting angles of the fibers to the image plane are measured. The resulting fiber cross sectional images are distorted to compensate the error due to fiber tilt, restoring the true fiber cross sectional shape. We use an approximated correction, the paper provides error estimates of the approximation. Measurement results for fiber wall thickness, fiber coarseness and fiber collapse are presented for one hardwood and one softwood pulp.

Survey of One-handed Lifting in Manufacturing Industry: A Cross-sectional Study of the BackWorks Study Cohort

2020 ◽  
Vol 64 (1) ◽  
pp. 942-946
Author(s):  
Ruoliang Tang ◽  
Jay M. Kapellusch ◽  
Andrew S. Merryweather ◽  
Matthew S. Thiese ◽  
Kurt T. Hegmann ◽  
...  
Keyword(s):  
Manufacturing Industry ◽  
Cross Sectional Study ◽  
Study Cohort ◽  
The European Union ◽  
Sectional Study ◽  
Cross Sectional ◽  
Materials Handling ◽  
Manual Materials Handling ◽  
Lost Productivity ◽  
The One

Low back pain (LBP) is a common health problem and a major cause of lost productivity in workplaces. Manual materials handling (MMH) jobs have traditionally been regarded as risk factor for LBP. Compared to two-handed lifting, one-handed lifting has received little attention in both epidemiological and biomechanical research. In addition, one frequent complaint of the revised NIOSH lifting equation (RNLE) has been the lack of capability to directly evaluate one-handed lifting. Modifications have been proposed by the European Union, however their efficacy and influence have not yet been evaluated. This cross-sectional study provided objective survey of the MMH jobs, especially the one-handed lifting performed in manufacturing industry and investigated the outcomes of three proposed methods to address one-handed lifting using RNLE approach. Preliminary results suggest that workers with some one-handed lifting are associated with higher physical exposure. However, the increase was more significant among those who perform primarily one-handed lifting.

Study of Correctly Expanded Sonic Jet with Air Tabs

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Arun Prasad R ◽  
Thanigaiarasu S ◽  
Sembaruthi M ◽  
Rathakrishnan E
Keyword(s):  
Numerical Study ◽  
Cross Sectional ◽  
Potential Core ◽  
Convergent Nozzle ◽  
Jet Mixing ◽  
Pressure Profiles ◽  
Constant Diameter ◽  
Sonic Jet ◽  
Sectional Shape ◽  
Length Reduction

AbstractThe present numerical study is to understand the effect of air tabs located at the exit of a convergent nozzle on the spreading and mixing characteristics of correctly expanded sonic primary jet. Air tabs used in this study are two secondary jets issuing from constant diameter tubes located diametrically opposite at the periphery of the primary nozzle exit, normal to the primary jet. Two air tabs of Mach numbers 1.0 to 1.4, in steps of 0.1 are considered in this study. The mixing modification caused by air tabs are analysed by considering the mixing of uncontrolled (free) primary jet as a reference. Substantial enhancement in jet mixing is achieved with Mach 1.4 air tabs, which results in 80 % potential core length reduction. The total pressure profiles taken on the plane (YZ) normal to the primary jet axis, at various locations along the primary jet centreline revealed the modification of the jet cross sectional shape by air tabs. The stream-wise vortices and bifurcation of the primary jet caused by air tabs are found to be the mechanism behind the enhanced jet mixing.

scholarly journals Reproducibility and agreement between three positions for handgrip assessment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Olga-Cecilia Vargas-Pinilla ◽  
Eliana-Isabel Rodríguez-Grande
Keyword(s):  
Supine Position ◽  
Cross Sectional Study ◽  
Sitting Position ◽  
Average Difference ◽  
Cross Sectional ◽  
Hand Grip ◽  
Standardization Process ◽  
The One ◽  
Level Of Agreement ◽  
Apparently Healthy

AbstractThe protocol established for taking hand grip dynamometry measurements determines that the patient must be in a sitting position. This protocol cannot be applied due to the patient’s conditions in some cases, such as abdominal surgery, musculoskeletal spine or hip injuries. The purpose was to determine the reproducibility and level of agreement between the Handgrip dynamometry in supine position with the elbow flexed or extended, and the one measured in the sitting position, the design was a descriptive cross-sectional study. The population were young apparently healthy between 18 and 30 years of age (N = 201). Handgrip measurement was performed on both upper limbs in a sitting position with a flexed elbow, a supine position with a flexed elbow, and supine position with the elbow extended. Reproducibility was nearly perfect in all positions (ICC 0.95–0.97). Regarding the level of agreement for the comparison between sitting and supine positions with a flexed elbow, an average difference of − 0.406. For supine position with an extended elbow and supine position with a flexed elbow, the average difference was − 1.479. Considering the results, clinicians or researchers can choose any of the positions evaluated herein and obtain reliable results as long as the standardization process is followed.

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