Evaluasi Karakteristik Mikro-Fisik dan Mekanik Pasir Vulkanik Tersementasi di Tebing Sungai Aliran Lahar Gunung Kelud

Tebing pasir vulkanik dengan material piroklastik hasil erupsi Gunung Kelud memiliki sifat unik yang terdapat pada struktur mikronya, yaitu fabrik yang porous dimana partikel dan pengikatnya akan saling mengunci atau tersementasi. Penelitian ini mengidentifikasi karakteristik mikro-fisik dan mineralogi pasir vulkanik tersementasi serta pengaruh terhadap kuat geser tebing. Analisa karakteristik fisik uji distribusi butiran bergradasi baik dan buruk dan nilai berat jenis tanah 2,783 – 2,803. Pengujian angka pori tanah dengan kerapatan Dr 50% didapat 0,713 – 0,775 dan Dr 70% didapat 0,639 – 0,720. Uji kapasitas absorpsi 6,383% - 7,759%. Scanning Electron Miroscopes mengidentifikasi adanya rongga udara yang tersebar di permukaan butiran yang dipenuhi partikel volcanic ash yang berukuran sangat halus dengan sphericity and roundness termasuk kedalam high sphericity dan kategori butiran angular hingga sub-angular berbentuk oblate. Analisa karakteristik mineralogi pengujian X-RD, SEM-EDX, dan X-RF menghasilkan kandungan total SiO2 + Al2O3 + Fe2O3 yaitu 80,3% - 82,8% bersifat pozolanik atau tersementasi. Analisa karakteristik mekanik pengujian geser langsung diperoleh harga sudut geser dalam 39,74˚ - 46,97˚ (Dr 50%) dan 42,84˚ - 47,81˚ (Dr 70%), sedangkan nilai sudut tenang sebesar 31,68˚ - 34,01˚.

Quantitative scanning-electron microscope analysis of volcanic ash surfaces: Application to the 1982-1983 Galunggung eruption (Indonesia)

Geological Society of America Bulletin ◽

10.1130/b26048.1 ◽

2007 ◽

Vol 119 (5-6) ◽

pp. 743-752 ◽

Cited By ~ 15

Author(s):

O. Ersoy ◽

A. Gourgaud ◽

E. Aydar ◽

G. Chinga ◽

J.-C. Thouret

Keyword(s):

Electron Microscope ◽

Volcanic Ash ◽

Scanning Electron Microscope Analysis ◽

Microscope Analysis ◽

Electron Microscope Analysis ◽

The texture of an english fuller's earth

Clay Minerals ◽

10.1180/claymin.1982.017.2.11 ◽

1982 ◽

Vol 17 (2) ◽

pp. 255-258 ◽

Cited By ~ 1

Author(s):

R. H. S. Robertson ◽

D. Tessier ◽

J. L. White

Keyword(s):

Electron Microscope ◽

Lower Cretaceous ◽

Volcanic Ash ◽

Glass Fragment ◽

Basaltic Glass ◽

Fuller’S Earth ◽

It is generally agreed that the English mid-Jurassic and Lower Cretaceous fuller's earths were derived from volcanic ash. In the Lower Cretaceous fuller's earth of Woburn, Kerr (1932) recognized partially decomposed relics of shards in a matrix of montmorillonite, and Grim (1933, 1935) described montmorillonite pseudomorphs after glass fragments in the Bath fuller's earth of Bathonian age. Jeans et al. (1977) published twenty-two SEM pictures of pyroclasts, including sanidine, sphene, trachytic pumice, and a basaltic glass fragment. Photomicrographs of the Lower Cretaceous fuller's earth show shard relicts ranging in length from 0·8-1·26 mm (median ∼1·12 mm) and in thickness from 5-15µm (Jeans et al., 1977, fig. 14a). However, much remains obscure about the shape, size and mode of packing of the argillized vitric particles which make up the bulk of fuller's earths. This note describes the texture of an English fuller's earth which was freeze-fractured (Tessier, 1978), prior to examination with a scanning electron microscope.

Shape and surface area measurements using scanning electron microscope stereo-pair images of volcanic ash particles

Geosphere ◽

10.1130/ges00558.1 ◽

2010 ◽

Vol 6 (6) ◽

pp. 805-811 ◽

Cited By ~ 22

Author(s):

Owen P. Mills ◽

William I. Rose

Keyword(s):

Electron Microscope ◽

Surface Area ◽

Volcanic Ash ◽

Stereo Pair ◽

Surface area and volume measurements of volcanic ash particles using micro-computed tomography (micro-CT): A comparison with scanning electron microscope (SEM) stereoscopic imaging and geometric considerations

Journal of Volcanology and Geothermal Research ◽

10.1016/j.jvolgeores.2010.08.004 ◽

2010 ◽

Vol 196 (3-4) ◽

pp. 281-286 ◽

Cited By ~ 22

Author(s):

Orkun Ersoy ◽

Erdal Şen ◽

Erkan Aydar ◽

İlkan Tatar ◽

H. Hamdi Çelik

Keyword(s):

Computed Tomography ◽

Electron Microscope ◽

Surface Area ◽

Volcanic Ash ◽

Micro Ct ◽

Micro Computed Tomography ◽

Volume Measurements ◽

Scanning Electron ◽

Area And Volume

MICROSCALE 3D-PRINTED MAPS AND STATISTICAL ANALYSIS OF STRUCTURAL AND GEOCHEMICAL CHARACTERISTICS OF VOLCANIC ASH FROM THE EYJAFJALLAJÖKULL VOLCANO IN ICELAND USING SCANNING ELECTRON MICROSCOPE AND 3D-ELEVATION SOFTWARE

10.1130/abs/2020se-345425 ◽

2020 ◽

Author(s):

Moread Achek ◽

◽

Antonios Marsellos

Keyword(s):

Electron Microscope ◽

Statistical Analysis ◽

Volcanic Ash ◽

Geochemical Characteristics ◽

3D Printed ◽

Comparing single-particle analysis data of volcanic ash of the 2010 Eyjafjallajökull eruption obtained from scanning electron and light microscope images

European Journal of Mineralogy ◽

10.1127/ejm/2016/0028-2555 ◽

2016 ◽

Vol 28 (5) ◽

pp. 855-868 ◽

Cited By ~ 1

Author(s):

Frank Sommer ◽

Christoph Maschowski ◽

Volker Dietze ◽

Bernard Grobéty ◽

Reto Gieré

Keyword(s):

Single Particle ◽

Light Microscope ◽

Volcanic Ash ◽

Analysis Data ◽

Particle Analysis ◽

Single Particle Analysis ◽

Microscope Images ◽

Influence of the Process of Synthesis of Zeolites from Volcanic Ash in Its Synergistic Action as a Flame-Retardant for Polypropylene Composites

Buildings ◽

10.3390/buildings12010024 ◽

2021 ◽

Vol 12 (1) ◽

pp. 24

Author(s):

Jonathan Almirón ◽

María Vargas ◽

Danny Tupayachy-Quispe ◽

Sophie Duquesne ◽

Francine Roudet ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Flame Retardant ◽

Volcanic Ash ◽

Morphological Structure ◽

Nitrogen Adsorption ◽

Synergistic Action ◽

Ammonium Polyphosphate ◽

Limiting Oxygen Index ◽

In this research, the influence of natural zeolites obtained from the volcanic ash of the Ubinas volcano has been studied as synergistic agents in a flame-retardant system (composed of ammonium polyphosphate, pentaerythritol, and polypropylene). Four zeolites were synthesized from volcanic ash, including those that had been calcined and those that had not. These were then placed in an alkaline solution at three synthesis temperatures. Zeolites were characterized through X-ray diffraction, specific surface area by nitrogen adsorption analysis (Brunauer–Emmett–Teller) and scanning electron microscopy. Polypropylene matrix composites were prepared with ammonium polyphosphate, pentaerythritol and zeolites at 1, 5 and 9%. Its thermal stability and fire resistance were evaluated by thermogravimetric analysis, limiting oxygen index, vertical burning test and cone calorimeter and its morphological structure by scanning electron microscopy. It was determined that the synthesis temperature and the use of calcined and without calcined volcanic ash have an influence on the characteristics of the zeolites and on its synergistic action.

Quantitative analysis on volcanic ash surfaces: Application of extended depth-of-field (focus) algorithm for light and scanning electron microscopy and 3D reconstruction

Micron ◽

10.1016/j.micron.2006.11.010 ◽

2008 ◽

Vol 39 (2) ◽

pp. 128-136 ◽

Cited By ~ 22

Author(s):

Orkun Ersoy ◽

Erkan Aydar ◽

Alain Gourgaud ◽

Hasan Bayhan

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Quantitative Analysis ◽

3D Reconstruction ◽

Volcanic Ash ◽

Depth Of Field ◽

Extended Depth Of Field ◽

Pathogenesis of Human Hair Defects

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010005007x ◽

1974 ◽

Vol 32 ◽

pp. 12-13

Author(s):

P.S. Porter ◽

T. Aoyagi ◽

R. Matta

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Human Hair ◽

Standard Techniques ◽

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

Morphology, Distribution and Identification of Micro-Constituents Along Grain Boundaries in Nickel-Base Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071326 ◽

1973 ◽

Vol 31 ◽

pp. 176-177

Author(s):

D. E. Fornwalt ◽

A. R. Geary ◽

B. H. Kear

Keyword(s):

Electron Microscope ◽

Grain Boundaries ◽

Volume Fraction ◽

Rupture Life ◽

Stress Rupture ◽

High Volume ◽

Precipitate Morphology ◽

Stress Rupture Life ◽

Nickel Base ◽

A systematic study has been made of the effects of various heat treatments on the microstructures of several experimental high volume fraction γ’ precipitation hardened nickel-base alloys, after doping with ∼2 w/o Hf so as to improve the stress rupture life and ductility. The most significant microstructural chan§e brought about by prolonged aging at temperatures in the range 1600°-1900°F was the decoration of grain boundaries with precipitate particles.Precipitation along the grain boundaries was first detected by optical microscopy, but it was necessary to use the scanning electron microscope to reveal the details of the precipitate morphology. Figure 1(a) shows the grain boundary precipitates in relief, after partial dissolution of the surrounding γ + γ’ matrix.