On the Possibility of Estimating the Average Surface Area of Solid Particles

1945 ◽  
Vol 13 (6) ◽  
pp. 249-249 ◽  
Author(s):  
Hans M. Cassel
Keyword(s):  
Surface Area ◽  
Solid Particles ◽  
Average Surface ◽  
Average Surface Area

scholarly journals Relation between leaf number and final leaf area of rye.

1964 ◽  
Vol 12 (1) ◽  
pp. 30-39
Author(s):  
R.F. Hoogland
Keyword(s):  
Leaf Area ◽  
Surface Area ◽  
Correlation Coefficients ◽  
Leaf Number ◽  
Total Leaf Area ◽  
Average Surface ◽  
Flag Leaves ◽  
Average Surface Area ◽  
Number Of Leaves ◽  
The Relationship

In rye cv. Petkus and Zelder the date of emergence of the flag leaves was almost the same for all plants irrespective of the number of leaves (10-13) produced. Correlation coefficients for the relationship between total leaf area and number of leaves were + 0.45 and + 0.44 and for that between number of spikelets per ear and number of leaves + 0.61 and + 0.69 for the 2 varieties, respectively. Average surface area per leaf increased with increasing number of leaves.-R.B. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Surface area analysis in edentulous jaws of patients with skeletal class I

2011 ◽  
Vol 58 (4) ◽  
pp. 209-215 ◽  
Author(s):  
Srdjan Postic
Keyword(s):  
Surface Area ◽  
Class I ◽  
Anthropometric Parameter ◽  
Average Surface ◽  
Skeletal Class ◽  
Surface Areas ◽  
Significant Difference ◽  
Average Surface Area ◽  
The Right ◽  
Edentulous Jaws

Introduction. The surface area of edentulous jaw has been considered as an important functional and anthropometric parameter. The aim of this study was to assess the surface area of supporting tissue in edentulous jaws of patients with the skeletal class I. Material and Methods. Thin aluminum foils (0.5 mm of thickness) were adapted on plaster surfaces of 139 pairs of edentulous jaws casts. Foils were positioned on a millimeter-paper in order to measure their areas. Additionally, surface areas were measured using a mechanic plan-meter (G. Coradi, Zurich, Switzerland, serial no. 49823). The measurement error was 1%. Skeletal class of edentulous jaws was determined by analysis of lateral cephalometric radiographs, and assessing the ANB (SNA, SNB) angle. Results. The average surface area of edentulous upper jaws was 4654?407 mm2 in males, and 4212?368 mm2 in females. Edentulous lower jaws had average surface area of 2843?339 mm2 in males, and 2334?295 mm2 in females. Statistically significant difference (p<0.001) was found in comparison of surface areas and dimensions of upper and lower edentulous jaws in male and female. ANB values ranged from 2 to 4 degrees. Conclusion. The surface area is an important parameter in the analysis of edentulous jaws. Edentulous jaws in males had greater surface areas and dimensions as compared to females. Edentulous areas on the right side were not absolutely symmetric to areas on the left side.

Morphology and dimensions of the young comendite lavas of La Primavera volcano, Mexico

1982 ◽  
Vol 119 (5) ◽  
pp. 477-485 ◽  
Author(s):  
B. J. Clough ◽  
J. V. Wright ◽  
G. P. L. Walker
Keyword(s):  
Surface Area ◽  
Quantitative Data ◽  
Average Thickness ◽  
Ring Fracture ◽  
Dry Land ◽  
Average Surface ◽  
Aspect Ratios ◽  
Average Surface Area ◽  
Special Environment ◽  
Lake Deposits

SummaryQuantitative data on the rhyolitic lavas of the Quaternary La Primavera volcano, Mexico, are presented. Lavas vary in form from domes and mesa lavas to short coulées. Average thickness is 100 m, average surface area is 2.7 km2 and aspect ratios vary from 1:7 to 1:25. Two petrological lava types are distinguished – porphyritic and aphyric. Porphyritic lavas occur on or within an inner ring fracture and are associated with an area of caldera lake deposits. Many features suggest that these porphyritic lavas were emplaced into the wet sediments or water of the caldera lake. Aphyric lavas are largely found to the south of this region and form large polygenetic structures extruded on dry land. The porphyritic lavas generally are smaller and have higher aspect ratios than the aphyric, which are attributed to their special environment of emplacement. Some porphyritic lavas extruded on dry land, outside the region occupied by the caldera lake, are, however, the thinnest on the volcano.

Sodium-pump density of cells from dog tracheal mucosa

1985 ◽  
Vol 248 (5) ◽  
pp. C389-C398 ◽  
Author(s):  
J. H. Widdicombe ◽  
C. B. Basbaum ◽  
E. Highland
Keyword(s):  
Surface Area ◽  
Sodium Pump ◽  
Apical Membrane ◽  
Cell Types ◽  
Total Surface Area ◽  
Basal Cells ◽  
Tracheal Mucosa ◽  
Average Surface ◽  
Surface Areas ◽  
Average Surface Area

Uptake of tritiated ouabain by cells isolated from dog tracheal epithelium showed two components: a saturable component with a Km of 5.1 X 10(-8) M and a maximal uptake of 8.3 X 10(5) molecules/cell and a nonsaturating component of uptake that was linear with concentration. Several criteria indicated that the saturable uptake component represented binding to the Na+-K+-ATPase. To estimate the average surface area per cell, a known number of cells were pelleted and weighed, and the average surface area was calculated, assuming the cells to be perfectly spherical. The validity of this assumption was confirmed by comparing the calculated surface areas of cells in isotonic and hypotonic media. From the values for maximal saturable uptake and average surface area, a pump density of approximately 2,400 sites/micron2 was calculated. Given that the apical membrane lacks Na pumps and accounts for only approximately 5% of the total surface area, this value corresponds to the pump density of the basolateral cell membrane. The pump densities of ciliated, goblet, and basal cells were compared by autoradiography. The three cell types had approximately the same density of pump sites.

Regression of corneal neovascularization: Adiponectin versus bevacizumab eye drops

2019 ◽  
pp. 112067211987494 ◽  
Author(s):  
Alireza Baradaran-Rafii ◽  
Azin Ashnagar ◽  
Saeed Heidari Keshel ◽  
Sayena Jabbehdari ◽  
Ghazaleh Baradaran-Rafii
Keyword(s):  
Surface Area ◽  
Average Length ◽  
Corneal Neovascularization ◽  
Silk Suture ◽  
Eye Drops ◽  
Artificial Tears ◽  
Control Groups ◽  
Average Surface ◽  
Average Surface Area ◽  
And Control

Purpose: Comparing the effect of adiponectin versus bevacizumab in decreasing corneal neovascularization. Methods: This study was conducted on 30 eyes of 30 New Zealand Albino male rabbits. Corneal neovascularization was induced by a single 7-0 silk suture 2 mm long and 1 mm in front of the limbus for 2 weeks. Rabbits were randomly divided into three groups of adiponectin (20 µg/mL), bevacizumab (5 mg/mL) and artificial tears. The treatments continued up to 14 days. Results: At the end of 14 days, the average length of vessels in rabbits treated with adiponectin, bevacizumab and control groups decreased from 2.12 ± 0.32 mm to 0.89 ± 0.46 mm (57.68% ± 19.98%) (P < 0.001), 2.30 ± 0.41 mm to 1.30 ± 0.58 mm (42.49% ± 27.17%) (P = 0.048) and from 2.12 ± 0.44 mm to 1.81 ± 0.42 mm (14.81% ± 5.64%) (P = 0.112), respectively. The length of vessels decreased 57.68% ± 19.98% and 42.49% ± 27.17% in adiponectin versus bevacizumab groups, respectively (P = 0.527). The average surface area of vessels in rabbits treated with adiponectin, bevacizumab and control groups reduced from 5.02 ± 1.50 mm2 to 1.40 ± 0.75 mm2 (70.64% ± 17.76%) (P < 0.001) 0.34 ± 1.1 mm2 to 2.80 ± 1.04 mm2 (48.24% ± 19.23%) (P = 0.039) and 5.12 ± 2.92 mm2 to 4.4 ± 2.55 mm2 (14.68% ± 4.19%) (P = 0.117). Mean surface area of vascularization decreased 70.64% ± 17.76% and 48.24% ± 19.23% in adiponectin versus bevacizumab, respectively (P = 0.013). Conclusions: The results of this study suggest that topical adiponectin can decrease recent corneal neovascularization.

Habitat characters of Tigriopus californicus (Copepoda: Harpacticoida), with notes on the dispersal of supralittoral fauna

1999 ◽  
Vol 79 (1) ◽  
pp. 85-92 ◽  
Author(s):  
James J. Powlik
Keyword(s):  
Surface Area ◽  
Wind Wave ◽  
Volume Ratio ◽  
Tidal Elevation ◽  
Tigriopus Californicus ◽  
Average Surface ◽  
Barkley Sound ◽  
Scytosiphon Lomentaria ◽  
Average Surface Area ◽  
Incidental Fauna

Supralittoral splashpools representing 312,000 m2 of shoreline in Barkley Sound, British Columbia, were surveyed seasonally for tidal elevation, size, water properties, macroflora and faunal constituents coincident with colonization by Tigriopus californicus (Arthropoda: Copepoda). Overall, 90.1% of pools containing T. californicus were found between 3.0 and 5.0 m above lowest normal tide, with an average surface area-to-volume ratio of 7.06. Copepod populations were found at water temperatures of 6–33°C; salinity of <1–139 psu; pH of 6.1–9.5; and of 1.1–13.7 mg l−1 oxygen. Sediment and vegetation was sparse in T. californicus pools (mean cover 15.79±10.6% in 9.4±11.1% of pools, all species), and consisted most commonly of Enteromorpha compressa and Scytosiphon lomentaria and its Ralfsia-like alternate phase. Common fauna included mites, amphipods, littorines, and nematodes, with the highest diversity of co-inhabitants occurring in spring. Factors such as wind, wave action, and incidental fauna are discussed as potential agents of dispersal for splashpool copepods.

scholarly journals Heterogeneous freezing of water droplets containing kaolinite particles

2011 ◽  
Vol 11 (9) ◽  
pp. 4191-4207 ◽  
Author(s):  
B. J. Murray ◽  
S. L. Broadley ◽  
T. W. Wilson ◽  
J. D. Atkinson ◽  
R. H. Wills
Keyword(s):  
Cooling Rate ◽  
Surface Area ◽  
Clay Mineral ◽  
Constant Temperature ◽  
Hydrophobic Surface ◽  
Supercooled Liquid ◽  
Stochastic Approach ◽  
Solid Particles ◽  
Rate Coefficients ◽  
Water Droplets

Abstract. Clouds composed of both ice particles and supercooled liquid water droplets exist at temperatures above ~236 K. These mixed phase clouds, which strongly impact climate, are very sensitive to the presence of solid particles that can catalyse freezing. In this paper we describe experiments to determine the conditions at which the clay mineral kaolinite nucleates ice when immersed within water droplets. These are the first immersion mode experiments in which the ice nucleating ability of kaolinite has been determined as a function of clay surface area, cooling rate and also at constant temperatures. Water droplets containing a known amount of clay mineral were supported on a hydrophobic surface and cooled at rates of between 0.8 and 10 K min−1 or held at constant sub-zero temperatures. The time and temperature at which individual 10–50 μm diameter droplets froze were determined by optical microscopy. For a cooling rate of 10 K min−1, the median nucleation temperature of 10–40 μm diameter droplets increased from close to the homogeneous nucleation limit (236 K) to 240.8 ± 0.6 K as the concentration of kaolinite in the droplets was increased from 0.005 wt% to 1 wt%. This data shows that the probability of freezing scales with surface area of the kaolinite inclusions. We also show that at a constant temperature the number of liquid droplets decreases exponentially as they freeze over time. The constant cooling rate experiments are consistent with the stochastic, singular and modified singular descriptions of heterogeneous nucleation; however, freezing during cooling and at constant temperature can be reconciled best with the stochastic approach. We report temperature dependent nucleation rate coefficients (nucleation events per unit time per unit area) for kaolinite and present a general parameterisation for immersion nucleation which may be suitable for cloud modelling once nucleation by other important ice nucleating species is quantified in the future.

The relationship between inner surface potential and electrokinetic potential from an experimental and theoretical point of view

2017 ◽  
Vol 14 (5) ◽  
pp. 295 ◽  
Author(s):  
Tajana Preočanin ◽  
Danijel Namjesnik ◽  
Matthew A. Brown ◽  
Johannes Lützenkirchen
Keyword(s):  
Surface Properties ◽  
Surface Potential ◽  
Single Particle ◽  
Surface Reactions ◽  
Solid Particles ◽  
Theoretical Point ◽  
Surface Characterisation ◽  
Layer Potential ◽  
Average Surface ◽  
Inner Surface

Environmental contextInterfacial properties of colloid and nanoparticles are directly related to the reactivity and surface densities of existing surface sites. Surface characterisation of particles provides only some kind of average surface properties. Analysis of well-defined monocrystal surfaces, which form the surface of the single particle, leads to a better understanding of surface reactions and mutual interactions of adjacent crystal planes on average surface properties. AbstractThe contact of small solid particles and macroscopic flat planes with aqueous electrolyte solutions results in the accumulation of ions at the interface and the formation of the electrical interfacial layer. Analysis of well-defined monocrystal surfaces, which are the building blocks of a single particle, leads to a better understanding of surface reactions and mutual interactions of adjacent crystal planes on average surface properties of particles. We analyse inner surface potential (obtained by single-crystal electrode) and zeta-potential data (obtained by streaming potential measurements) that were obtained on identical samples. Among the systems for which comparable surface and zetapotentials are available, measured inner surface potential data for sapphire (0001), haematite (0001) and rutile (110) show the expected behaviour based on the face-specific surface chemistry model, whereas the slopes for rutile (110) and quartz (0001) do not. Isoelectric points for sapphire (0001), haematite (0001) and rutile (100) are in conflict with the standard model that implies consistent behaviour of surface potential and diffuse layer potential. For the two former systems, previous results from the literature suggest that the charge of interfacial water can explain the discrepancy. The water layer could also play a role for quartz (0001), but in this case, the discrepancy would simply not be noticed, because both point of zero potential and isoelectric point are low. Along with data on silver halides, it can be concluded that six-ring water structures on solids may generate the electrokinetic behaviour that is typical of inert surfaces like Teflon.

scholarly journals Comparison of Exposure in the Kaplan Versus the Kocher Approach in the Treatment of Radial Head Fractures

Hand ◽  
2018 ◽  
Vol 14 (2) ◽  
pp. 253-258 ◽  
Author(s):  
Leslie Fink Barnes ◽  
Joseph Lombardi ◽  
Thomas R. Gardner ◽  
Robert J. Strauch ◽  
Melvin P. Rosenwasser
Keyword(s):  
Surface Area ◽  
Radial Head ◽  
Lateral Collateral Ligament ◽  
Radial Head Fractures ◽  
3 Dimensional ◽  
Average Surface Area ◽  
The Mean ◽  
The Difference ◽  
Head Neck

Background: The aim of this study was to compare the complete visible surface area of the radial head, neck, and coronoid in the Kaplan and Kocher approaches to the lateral elbow. The hypothesis was that the Kaplan approach would afford greater visibility due to the differential anatomy of the intermuscular planes. Methods: Ten cadavers were dissected with the Kaplan and Kocher approaches, and the visible surface area was measured in situ using a 3-dimensional digitizer. Six measurements were taken for each approach by 2 surgeons, and the mean of these measurements were analyzed. Results: The mean surface area visible with the lateral collateral ligament (LCL) preserved in the Kaplan approach was 616.6 mm2 in comparison with the surface area of 136.2 mm2 visible in the Kocher approach when the LCL was preserved. Using a 2-way analysis of variance, the difference between these 2 approaches was statistically significant. When the LCL complex was incised in the Kocher approach, the average visible surface area of the Kocher approach was 456.1 mm2 and was statistically less than the Kaplan approach. The average surface area of the coronoid visible using a proximally extended Kaplan approach was 197.8 mm2. Conclusions: The Kaplan approach affords significantly greater visible surface area of the proximal radius than the Kocher approach.

Exfoliation of MoS2 Catalysts: Structural and Catalytic Changes

1994 ◽  
Vol 351 ◽  
Author(s):  
M. Del Valle ◽  
M. Avalos-Borja ◽  
J. Cruz ◽  
S. Fuentes
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Molybdenum Sulfide ◽  
Original Structure ◽  
Sulfide Catalysts ◽  
Average Surface ◽  
Chemical Exfoliation ◽  
Average Surface Area ◽  
Mos2 Catalysts ◽  
Thiophene Hds

ABSTRACTA study of the microstructural differences between exfoliated and non-exfoliated MoS2-based materials is presented, relating them to differences in their catalytic activity. Both commercial (crystalline) MoS2 and molybdenum sulfide catalysts prepared by thiosalt decomposition are subjected to chemical exfoliation reported to separate MoS2 monolayers from the original structure. Electron microscopy results show that the chemical treatment yields non-typical MoS2 nanostructures. Average surface area is also modified by exfoliation. The thiophene HDS activity of commercial MoS2 increases after exfoliation, while it decreases after exfoliation in the case of MoS2 catalysts.

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