scholarly journals Concentration of elements in mitotic chromatin as measured by x-ray microanalysis.

1977 ◽  
Vol 73 (1) ◽  
pp. 193-199 ◽  
Author(s):  
I L Cameron ◽  
R L Sparks ◽  
K L Horn ◽  
N R Smith

Unfixed frozen-dried and uncoated tissue sections of the mouse duodenum were placed on carbon planchets and analyzed in a scanning electron microscope fitted with energy dispersive X-ray equipment. Computer analysis of the X-ray spectra allowed elemental microanalysis of the nucleus, cytoplasm, and mitotic chromatin regions in the cryptal and villus enterocytes. The peak to continuum ratio of S, Cl, K, and Ca were higher in mitotic chromatin than any of the other sites measured. The redistribution of Ca at mitosis is postulated to help explain both chromosome condensation and assembly of the mitotic spindle apparatus.

2015 ◽  
Vol 799-800 ◽  
pp. 125-129
Author(s):  
Mary Donnabelle L. Balela ◽  
April Alexa S. Lagarde ◽  
Stephen Jann A. Tamayo ◽  
Nikko S. Villareal ◽  
Ann Marielle Parreno

Zirconia (ZrO2) nanotubes were synthesized by anodization of zirconium (Zr) foil in NH4Fand (NH4)2SO4 aqueous solution. Different surface preparation methods (electropolishing and etching) were applied on the Zr foil prior to anodizaton. In addition, the anodization time and NH4F concentration were varied. The structure and morphologies of the nanotubes and their crystallinity were confirmed using scanning electron microscope and x-ray diffractometer, respectively. ZrO2 nanotubes with large diameters and thick walls were formed at lower NH4F concentration and longer anodization time. On the other hand, smaller nanotubes with thinner walls were produced when the NH4F concentration was increased. The synthesized nanotubes were predominantly tetragonal ZrO2 with small amounts of monoclinic ZrO2.


2009 ◽  
Vol 610-613 ◽  
pp. 215-219
Author(s):  
Xiao Jun Chen ◽  
Biao Wang ◽  
Hua Ping Wang ◽  
Qiong Juan Duan

Titania cloth was successfully prepared by the process comprising the steps of (1) immersing a cellulose fabric into titanium compound solution and (2) heating the impregnated fabric under controlled conditions. Several methods such as TG-DTA measurement, X-ray power diffraction (XRD), scanning electron microscope (SEM) were used to characterize the structure and properties of TiO2 cloth. And the TiO2 cloth sintered at 500°C exhibited the highest photodegradation efficiency of MB relative to the other samples.


2011 ◽  
Vol 356-360 ◽  
pp. 106-109 ◽  
Author(s):  
Yan Ling Bao ◽  
Guang Ze Dai ◽  
Chuan Jiang

PAN-based carbon fiber (CF) was modified by hypochlorous and urea in current treatments. The CF surface morphology and natures were characterized by specific facilities, such as scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and the degree of moisture. On the other hand, the biocompatibility nature was indicated by immobilization results of microorganisms on CF. The results show that the surface hydrophilicity and roughness of CF surface would contribute greatly to improve the immobilization ability of microorganisms on CF surface, and the produced oxygen on CF has more effect on microorganism immobilization than nitrogen.


Author(s):  
R. E. Ferrell ◽  
G. G. Paulson

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.


Author(s):  
W. Brünger

Reconstructive tomography is a new technique in diagnostic radiology for imaging cross-sectional planes of the human body /1/. A collimated beam of X-rays is scanned through a thin slice of the body and the transmitted intensity is recorded by a detector giving a linear shadow graph or projection (see fig. 1). Many of these projections at different angles are used to reconstruct the body-layer, usually with the aid of a computer. The picture element size of present tomographic scanners is approximately 1.1 mm2.Micro tomography can be realized using the very fine X-ray source generated by the focused electron beam of a scanning electron microscope (see fig. 2). The translation of the X-ray source is done by a line scan of the electron beam on a polished target surface /2/. Projections at different angles are produced by rotating the object.During the registration of a single scan the electron beam is deflected in one direction only, while both deflections are operating in the display tube.


Author(s):  
Marc H. Peeters ◽  
Max T. Otten

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.


Arena Tekstil ◽  
2013 ◽  
Vol 28 (1) ◽  
Author(s):  
Maya Komalasari ◽  
Bambang Sunendar

Partikel nano TiO2 berbasis air dengan pH basa telah berhasil disintesis dengan menggunakan metode sol-gel dan diimobilisasi pada kain kapas dengan menggunakan kitosan sebagai zat pengikat silang. Sintesis dilakukan  dengan prekursor TiCl4 pada konsentrasi 0,3 M, 0,5 M dan 1 M, dan menggunakan templat kanji dengan proses kalsinasi pada suhu 500˚C selama 2 jam. Partikel nano TiO2 diaplikasikan ke kain kapas dengan metoda pad-dry-cure dan menggunakan kitosan sebagai crosslinking agent. Berdasarkan hasil Scanning Electron Microscope (SEM),diketahui bahwa morfologi partikel TiO2 berbentuk spherical dengan ukuran nano (kurang dari 100 nm). Karakterisasi X-Ray Diffraction (XRD) menunjukkan adanya tiga tipe struktur kristal utama, yaitu (100), (101) dan (102) dengan fasa kristal yang terbentuk adalah anatase dan rutile. Pada karakterisasi menggunakan SEM terhadap serbuk dari TiO2 yang telah diaplikasikan ke permukaan kain kapas, terlihat adanya imobilisasi partikel nano TiO2 melalui ikatan hidrogen silang dengan kitosan pada kain kapas. Hasil analisa tersebut kemudian dikonfirmasi dengan FTIR (Fourier Transform Infra Red) yang hasilnya memperlihatkan puncak serapan pada bilangan gelombang 3495 cm-1, 2546 cm-1, dan 511 cm-1,  yang masing-masing diasumsikan sebagai adanya vibrasi gugus fungsi O-H, N-H dan Ti-O-Ti. Hasil SEM menunjukkan pula bahwa kristal nano yang terbentuk diantaranya adalah fasa rutile , yang berdasarkan literatur terbukti dapatberfungsi sebagai anti UV.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4045
Author(s):  
Rafał Mech ◽  
Jolanta Gąsiorek ◽  
Amadeusz Łaszcz ◽  
Bartosz Babiarczuk

The paper presents a comparison of the results of the corrosion resistance for three Fe-B-Co-Si-based newly developed alloys with the addition of Nb and V. The corrosion performance differences and microstructure variations were systematically studied using scanning electron microscope, electric corrosion equipment, X-ray diffractometer, and differential calorimeter. It has been shown that each alloying addition increased the corrosion resistance. The highest corrosion resistance obtained by potentiodynamic polarization was found for the alloy with both Nb and V addons (Fe57Co10B20Si5Nb4V4) and lowest in the case of the basic four-element Fe62Co15B14Si9 material. This shows that the proper choice of additions is of significant influence on the final performance of the alloy and allows tailoring of the material for specific applications.


2013 ◽  
Vol 19 (S2) ◽  
pp. 692-693
Author(s):  
P. Trimby

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.


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