Correlation of ameloblast size with enamel prism Pattern: use of scanning electron microscope to make surface area measurements

1968 ◽  
Vol 93 (4) ◽  
pp. 583-593 ◽  
Author(s):  
A. Boyde
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Area ◽  
Enamel Prism ◽  
Scanning Electron

scholarly journals Micropore Structure and Fractal Characteristics of Low-Permeability Coal Seams

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Guang-zhe Deng ◽  
Rui Zheng
Keyword(s):  
Fractal Dimension ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Coal Seam ◽  
Linear Relationship ◽  
Surface Area ◽  
Pore Volume ◽  
Low Permeability ◽  
Coal Seams ◽  
Scanning Electron

With the raw coal from a typical low-permeability coal seam in the coalfield of South Junger Basin in Xinjiang as the research object, this paper examined six kinds of coal samples with different permeabilities using a scanning electron microscope and a low-temperature nitrogen adsorption test that employed a JSM-6460LV high-resolution scanning electron microscope and an ASAP2020 automatic specific surface area micropore analyzer to measure all characteristic micropore structural parameters. According to fractal geometry theory, four fractal dimension calculation models of coal and rock were established, after which the pore structure characteristic parameters were used to calculate the fractal dimensions of the different coal seams. The results show that (1) the low-permeability coal seam in the coalfield of South Junger Basin in Xinjiang belongs to mesoporous medium, with a certain number of large pores and no micropores. The varying adsorption capacities of the different coal seams were positively correlated with pore volume, surface area, and the mesoporous surface area proportions, from which it was concluded that mesopores were the main contributors to pore adsorption in low-permeability coal seams. (2) The raw coal pore fractal dimension had a negative linear relationship to average pore size, a positive linear relationship with total pore volume, total surface area, and adsorption capacity, and a positive correlation with the mesoporous surface area proportion; that is, the higher the fractal dimension, the larger the pore volume and surface area of the raw coal. (3) The permeability of the low-permeability coal seam had a phase correlation with the micropore development degree; that is, the permeability had a phase negative correlation with the pore distribution fractal dimension, and there was a positive correlation between permeability and porosity. These results are of theoretical significance for the clean exploitation of low-permeability coal seam resources.

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

Geosphere ◽  
2010 ◽  
Vol 6 (6) ◽  
pp. 805-811 ◽  
Author(s):  
Owen P. Mills ◽  
William I. Rose
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Area ◽  
Volcanic Ash ◽  
Stereo Pair ◽  
Scanning Electron

scholarly journals Synthesis ofMnO2Microfiber with Secondary Nanostructure by Cotton Template

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Huan-qin Wang ◽  
Ming-bo Zheng ◽  
Jin-hua Chen ◽  
Guang-bin Ji ◽  
Jie-ming Cao
Keyword(s):  
Crystal Structure ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Single Crystal ◽  
Surface Area ◽  
Single Crystal Structure ◽  
Bet Surface Area ◽  
Low Concentration ◽  
Adsorption Desorption ◽  
Scanning Electron

HierarchicalMnO2microfibers were prepared by using cotton as the template andKMnO4as the precursor via an ultrasonic assistance route. The results of scanning electron microscope characterization showed that the concentration ofKMnO4had a significant effect on the morphology ofMnO2microfiber. At low concentration ofKMnO4, the microfiber was composed ofMnO2nanorods with single crystal structure. With increasing the concentration ofKMnO4, the secondary nanostructure ofMnO2microfibers had a transformation from nanorod to nanoparticle. The results ofN2adsorption-desorption analysis indicated thatMnO2microfibers had BET surface area of about 25 m2/g. This synthesis provides a new way to control the secondary nanostructure ofMnO2microfiber by adjusting the concentration of precursor. Furthermore, the mechanism for the replication was proposed and discussed.

scholarly journals The Effect of Fly Ash on Some Surface Characteristics and Microstructure of β-C2S

1997 ◽  
Vol 15 (6) ◽  
pp. 407-417
Author(s):  
Kh.A. Khalil ◽  
A.A. Amer
Keyword(s):  
Electron Microscope ◽  
Fly Ash ◽  
Scanning Electron Microscope ◽  
Specific Surface ◽  
Surface Area ◽  
Nitrogen Adsorption ◽  
Surface Characteristics ◽  
Ash Content ◽  
Sem Investigation ◽  
Scanning Electron

The effect of the addition of fly ash (0–15 wt. %) on the surface characteristics of β-C2S and its microstructure was investigated using nitrogen adsorption at −196°C together with scanning electron microscope (SEM) techniques. The results obtained revealed that the addition of fly ash up to 5 wt. % increased the specific surface area by 32% followed by a decrease of 34% when the fly ash content was increased up to 15 wt. %. SEM investigation showed that the hydrates produced form an outer shell which coats the fly ash particles.

scholarly journals Characteristics of Particles and Debris Released after Implantoplasty: A Comparative Study

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 602
Author(s):  
Xixi Wu ◽  
Changjie Cai ◽  
Javier Gil ◽  
Elizabeth Jantz ◽  
Yacoub Al Sakka ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Chemical Composition ◽  
Scanning Electron Microscope ◽  
Surface Area ◽  
Particle Number ◽  
Significant Difference ◽  
Group A ◽  
Particle Sizer ◽  
Group B ◽  
Scanning Electron

Titanium particles embedded on peri-implant tissues are associated with a variety of detrimental effects. Given that the characteristics of these detached fragments (size, concentration, etc.) dictate the potential cytotoxicity and biological repercussions exerted, it is of paramount importance to investigate the properties of these debris. This study compares the characteristics of particles released among different implant systems (Group A: Straumann, Group B: BioHorizons and Group C: Zimmer) during implantoplasty. A novel experimental system was utilized for measuring and collecting particles generated from implantoplasty. A scanning mobility particle sizer, aerodynamic particle sizer, nano micro-orifice uniform deposit impactor, and scanning electron microscope were used to collect and analyze the particles by size. The chemical composition of the particles was analyzed by highly sensitive microanalysis, microstructures by scanning electron microscope and the mechanical properties by nanoindentation equipment. Particles released by implantoplasty showed bimodal size distributions, with the majority of particles in the ultrafine size range (<100 nm) for all groups. Statistical analysis indicated a significant difference among all implant systems in terms of the particle number size distribution (p < 0.0001), with the highest concentration in Group B and lowest in Group C, in both fine and ultrafine modes. Significant differences among all groups (p < 0.0001) were also observed for the other two metrics, with the highest concentration of particle mass and surface area in Group B and lowest in Group C, in both fine and ultrafine modes. For coarse particles (>1 µm), no significant difference was detected among groups in terms of particle number or mass, but a significantly smaller surface area was found in Group A as compared to Group B (p = 0.02) and Group C (p = 0.005). The 1 first minute of procedures had a higher number concentration compared to the second and third minutes. SEM-EDS analysis showed different morphologies for various implant systems. These results can be explained by the differences in the chemical composition and microstructures of the different dental implants. Group B is softer than Groups A and C due to the laser treatment in the neck producing an increase of the grain size. The hardest implants were those of Group C due to the cold-strained titanium alloy, and consequently they displayed lower release than Groups A and B. Implantoplasty was associated with debris particle release, with the majority of particles at nanometric dimensions. BioHorizons implants released more particles compared to Straumann and Zimmer. Due to the widespread use of implantoplasty, it is of key importance to understand the characteristics of the generated debris. This is the first study to detect, quantify and analyze the debris/particles released from dental implants during implantoplasty including the full range of particle sizes, including both micro- and nano-scales.

Comparing the DBT Conversion by Using Crystalline WS2 and WS2 Electron Irradiated Catalyst

1998 ◽  
Vol 549 ◽  
Author(s):  
R. Rangel ◽  
G. Alonso ◽  
E. Adem ◽  
S. Fuentes ◽  
D. H. Galvan
Keyword(s):  
Catalytic Activity ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Area ◽  
Rate Constants ◽  
Initial Rate ◽  
Microstructural Changes ◽  
X Ray ◽  
Sem Micrographs ◽  
Scanning Electron

AbstractA catalytic study has been performed in WS2 irradiated with electrons at 1000 kGy. The purpose is to compare irradiated WS2 with WS2 crystalline in terms of DBT conversion, selectivity and surface area analysis. Also, Scanning Electron Microscope (SEM), X-raydiffraction were performed to show microstructural changes induced by irradiation. We found that DBT conversion increased by 55 % if compared with WS2 crystalline. The surface area decreased and the initial rate constants increased by a factor of four times. The selectivity for DCH after irradiation has decreased, while the selectivity for DIF and PCH has increased substantially. The DYH/DHS ratio has decreased in 42 %. The SEM micrographs showed that irradiation, at this level, produced certain damage in the crystallinity. The X-ray analysis showed different distribution in the intensity of the principal peaks after irradiation was achieved. This behavior could be correlated to the surface area decrement and the enhancing of the catalytic activity in WS2.

scholarly journals AKTIVASI ZEOLIT ALAM SEBAGAI ADSORBEN LOGAM BERAT Mg, Al, dan ZnO MENGGUNAKAN LARUTAN NaOH

2019 ◽  
Vol 6 (3) ◽  
Author(s):  
Widi Kapita Putri ◽  
Sabani Sabani
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Adsorption ◽  
Scanning Electron

Hasil zeolit alam yang berasal Tapanuli Selatan (Pahae) yang telah disintesis dengan metode kopresipitasi menggunakan variasi waktu yaitu variasi waktu 120,150, dan 180 menit menjadi nano zeolit. Nano zeolit tersebut kemudian dikarakterisasi dengan X-Ray Diffraction dan Scanning Electron Microscope- Energy Dispertion. Karakterisasi  dengan menggunakan XRD bertujuan untuk menentukan kemurnian dari nano zeolit yang sudah disintesis. Adapun tujuan untuk penelitian ini adalah mengetahui ukuran zeolit, struktur morfologinya, luas permukaannya dan daya adsorbsi zeolit. Hasil karakterisasi dari X-Ray Diffraction menunjukkan bahwa ukuran diameter kristalin nano zeolit variasi waktu 120 menit, 150 menit, dan 180 menit adalah 28,57 nm, 37,18 nm, dan 45,53 nm. Hasil karakterisasi Scanning Electron Microscope- Energy Dispertion dari nano zeolit variasi waktu 120, 150 dan 180 menit menunjukkan bahwa terjadi pengurangan aglomerasi dan permukaan nano zeolit lebih halus. Hasil pengujian Surface Area Analyzer  yang paling optimal terjai pada waktu 150 menit dengan nilai 108.320 m2/g. Sedangkan perhitungan % kesalahan yang paling optimal pada waktu 120 menit dengan 9.1763%.Hasil analisis uji Atomic Adsorption Spectrofotometric menunjukkan bahwa penyerapan kandungan logam atau daya adsorbsi  yang optimal yaitu pada logam Mg variasi waktu 180 menit adalah 99,99 % dibandingkan dengan penyerapan logam menggunakan zeolit waktu 150 menit dan 120 menit yaitu 99,95% dan 99,23%. Hasil karakterisasi dan pengujian dapat dijadikan acuan dalam mengukur potensi Zeolit Alam teraktivasi sebagai media adsorben. Maka dapat disimpulkan penggunaan zeolit sebagai adsorben mampu menyerap logam Mg secara optimal dengan nilai serap 99,99%.Kata Kunci : Zeolit, Metode kopresipitasi, Adsorben

scholarly journals Characterization of Alum Sludge for Reuse and Disposal

2012 ◽  
Vol 8 (4) ◽  
Author(s):  
Hanim Awab ◽  
P.T. Thanalechumi Paramalinggam ◽  
Abdull Rahim Mohd Yusoff
Keyword(s):  
Heavy Metals ◽  
Particle Size ◽  
Electron Microscope ◽  
Water Treatment ◽  
Scanning Electron Microscope ◽  
Bulk Density ◽  
Surface Area ◽  
Particle Density ◽  
Ash Content ◽  
Scanning Electron

The properties of spent drinking water treatment sludge (WTS) were investigated to determine its physical and chemical properties. WTS was obtained from the Semanggar Water Treatment Plant, Kota Tinggi, Johore, Malaysia. Bulk density, particle density, porosity, surface area, particle size, moisture content, ash content, chemical composition, leachability of heavy metals, pH and the total organic carbon (TOC) were determined. Surface and other physicochemical properties were also studied using the scanning electron microscope (SEM), field emission scanning electron microscope (FESEM), X-ray diffractometer (XRD), TGA, FTIR, BET single point surface area analyzer, and TOC analyzer. Results showed that the particle size, bulk density and particle density of WTS were 2-5 μm, 0.831 ± 0.061 g/cm3 and 2.66 ± 0.029 g/cm3, respectively. The porosity was 68-69% with surface of 38.92 m2/g and ash content of 67%, reflecting the high TOC of 1440.37±14.71. The sludge contained 29% moisture and showed a pH value of 4.28 in solution. Analysis of acid digest indicated a high content of Al and Fe. The WTS were shown to leach very low levels of selected heavy metals.

Preparation of Pd/PPy/Foam-Ni Electrode and its Electrocatalytic Hydrodechlorination of Dichlorophenols

2021 ◽  
Vol 1035 ◽  
pp. 1078-1088
Author(s):  
Zhen Peng Ma ◽  
Shu Xia Zhang ◽  
Zhi Gang Yang
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Specific Surface ◽  
Surface Area ◽  
Removal Efficiency ◽  
Specific Surface Area ◽  
Supporting Electrolyte ◽  
Electrocatalytic Hydrogenation ◽  
Ni Substrate ◽  
Scanning Electron

Based on mechanism of ECH (Electrocatalytic Hydrogenation),the Pa/PPy/Foam-Ni (Pd/PPY/Ni) prepared by electrical depositing was used as cathode to detoxifythree kinds of dichlorophenol (DCP) and improve their biodegradability. According to the dechloridation ability of electrodes prepared under different conditions, the factors were optimized. The removal efficiency of 2,4-dichlorophenol（2,4-DCP）reaches 64.45% when the supporting electrolyte is p-toluenesulfonic acid and the voltage is 0.6V and polymerizing time is 20mins. Analyzing the photograph from SEM (Scanning Electron Microscope), it shows that PPy (PolyPyrrole) changes depositing properties of Pa on foam-Ni substrate, which increases specific surface area and special ductility so as to benefit Pd to deposite on Ni substrate and improve ECH.

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