scholarly journals Evaluating the Emergence and Biochemical Changes of Primed Seeds in Proso Millet (Panicum miliaceum L.)

2019 ◽  
pp. 1-7
Author(s):  
R. Sridevi ◽  
V. Manonmani
Keyword(s):  
Cell Proliferation ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Pseudomonas Fluorescens ◽  
Biochemical Parameters ◽  
Free Sugars ◽  
Proso Millet ◽  
Scanning Electron ◽  
Better Than

The present study aimed in exploring the performance of primed seeds in enhancing the quality of proso millet. The primed seeds along with nonprimed seeds were evaluated for emergence, cell proliferation in radicle cells using scanning electron microscope and biochemical parameters. Seeds primed with Pseudomonas fluorescens 20% possessing higher germination and anatomical changes observed through scanning electron microscope revealed more cell proliferation which was found to show rapid cell elongation and cell division of the radicle when compared to nonprimed seeds. The biochemical causes responsible for higher invigorative effect were identified as enhanced enzyme activity recorded through α-amylase content, dehydrogenase activity, protein content, lipase activity, antioxidative enzymes like catalase activity, peroxidase activity and superoxide dismutase with lower electrical conductivity, free amino acid and free sugars of the seed leachate. It is concluded in this study that primed seeds of Pseudomonas fluorescens 20% performed better than other treatments through their exhibition of higher emergence, more cell proliferation and enhanced biochemical parameters.

Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

1971 ◽  
Vol 29 ◽  
pp. 26-27
Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike
Keyword(s):  
Electron Microscope ◽  
Image Quality ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Image Contrast ◽  
Objective Lens ◽  
Thick Specimen ◽  
Transmission Electron ◽  
Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

Resolution and measurement in the scanning electron microscope

1987 ◽  
Vol 45 ◽  
pp. 534-537 ◽  
Author(s):  
Michael T. Postek
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Engineering Design ◽  
Resolving Power ◽  
Practical Applications ◽  
Instrument Resolution ◽  
Accurate Definition ◽  
Definition Of ◽  
Scanning Electron ◽  
Better Than

The term ultimate resolution or resolving power is the very best performance that can be obtained from a scanning electron microscope (SEM) given the optimum instrumental conditions and sample. However, as it relates to SEM users, the conventional definitions of this figure are ambiguous. The numbers quoted for the resolution of an instrument are not only theoretically derived, but are also verified through the direct measurement of images on micrographs. However, the samples commonly used for this purpose are specifically optimized for the measurement of instrument resolution and are most often not typical of the sample used in practical applications.SEM RESOLUTION. Some instruments resolve better than others either due to engineering design or other reasons. There is no definitively accurate definition of how to quantify instrument resolution and its measurement in the SEM.

The Determination and Application of the Point Spread Function in the Scanning Electron Microscope

2018 ◽  
Vol 24 (4) ◽  
pp. 396-405 ◽  
Author(s):  
Matthew D. Zotta ◽  
Mandy C. Nevins ◽  
Richard K. Hailstone ◽  
Eric Lifshin
Keyword(s):  
Spatial Distribution ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Beam Current ◽  
Beam Shape ◽  
Practical Applications ◽  
Energy Beam ◽  
Working Distance ◽  
Scanning Electron

AbstractA method is presented to determine the spatial distribution of electrons in the focused beam of a scanning electron microscope (SEM). Knowledge of the electron distribution is valuable for characterizing and monitoring SEM performance, as well as for modeling and simulation in computational scanning electron microscopy. Specifically, it can be used to characterize astigmatism as well as study the relationship between beam energy, beam current, working distance, and beam shape and size. In addition, knowledge of the distribution of electrons in the beam can be utilized with deconvolution methods to improve the resolution and quality of backscattered, secondary, and transmitted electron images obtained with thermionic, FEG, or Schottky source instruments. The proposed method represents an improvement over previous methods for determining the spatial distribution of electrons in an SEM beam. Several practical applications are presented.

Voltage and Dopant Concentration Measurements of Semiconductors using a Band-Pass Toroidal Energy Analyzer Inside a Scanning Electron Microscope

2015 ◽  
Vol 21 (4) ◽  
pp. 910-918 ◽  
Author(s):  
Avinash Srinivasan ◽  
Anjam Khursheed
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Dopant Concentration ◽  
High Signal ◽  
Energy Analyzer ◽  
Order Of Magnitude ◽  
Band Pass ◽  
Concentration Measurements ◽  
Scanning Electron ◽  
Better Than

AbstractThis paper presents experimental results obtained from a scanning electron microscope (SEM) second-order focusing toroidal electron energy analyzer attachment. The results demonstrate that the analyzer can be used to obtain high signal-to-noise voltage and dopant concentration measurements on semiconductors in the presence of different electric field conditions at the sample. The experimentally calculated relative error of measurement typically varies from 31 to 63, corresponding to secondary electron (SE) signal mean shifts of 9–18 mV. The millivolt accuracy of these results is over one order of magnitude better than earlier quantitative dopant concentration measurements made by a retarding field analyzer.

scholarly journals Preparo inicial em periodontia: avaliações perfilométricas e microscópias pós-remoção de excesso cervicais de restaurações

2021 ◽  
pp. 73-80
Author(s):  
Raul G. Caffesse ◽  
José D. Freitas Vale
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Class Ii ◽  
Measuring Instrument ◽  
Combined Use ◽  
The Mean ◽  
Amalgam Restorations ◽  
Scanning Electron ◽  
Better Than

Forty recently extracted teeth with Class II amalgam restorations with overhangs were divided in four groups of ten teeth each. The overhangs were removed using one of the following instruments in each gruop: trimmer, chisel, surgical blade and reciprocating.motor.driven diamond tip. Instrumentation was performed until no irregularity could be detected clinically with a nº 3 explorer. The tooth.amalgam interfaces were examined by combined use of a surface measuring instrument and a scanning electron microscope. Four tracings from each specimen were recorded and the vertical discrepancy at the tooth.restoration interfaces measured. The mean score for tooth was determined, and the results were photographed aí 140 magnification with the SEM. The results indicated that all instruments tested were effective in removing overhangs, since none of the discrepancies registered after instrumenntation exceeded 4 Um. The surgical blade, and especially the reciprocting-motor.driven diamond tip eliminated overhangs better than the chisel. Both SEM photographs and the profilometric tracing revealed gaps at the tooth amalgam interface, rancing from 10 t o 50 Um in width.

Qualitative Analysis and Study the Workpiece Shearing Surface Quality of Fine-Blanking with Negative Clearance

2011 ◽  
Vol 697-698 ◽  
pp. 371-376
Author(s):  
Hong Du ◽  
Zhong Mei Zhang
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Qualitative Analysis ◽  
Surface Quality ◽  
Reference Value ◽  
Quality Standard ◽  
Fine Blanking ◽  
Negative Clearance ◽  
Scanning Electron

The workpieces of fine blanking with negative clearance were obtained through the fine-blanking with negative clearance processing experiment. The fractography photographs of workpieces shearing surface were scanned by scanning electron microscope (SEM), and the characterization parameters and quality standard of workpieces shearing surface with negative clearance were analyzed in the processing of blanking. According to the characterization parameters and quality standard of workpieces shearing surface with negative clearance, the workpiece with the length ratio of burnish band, deflection error, rollover error and blanking burr were analyzed qualitative. The findings have a certain reference value to the blanking related profession.

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