scholarly journals Analysis of Film Forming Law and Characteristics for an Air Static Spray with a Variable Position of the Plane

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1236
Author(s):  
Yi Liu ◽  
Yong Zeng ◽  
Xueya Zhao ◽  
Jiuxuan Liu ◽  
Dezhi Liu

In order to accurately establish the film thickness distribution model of a static spraying plane with air gun displacement, the film forming law and characteristics of the static spraying plane with air gun displacement were analyzed. The spray simulation model was established by the Euler–Euler method, and the spray process and film forming condition were calculated. The numerical simulation results show that oblique spraying has a large influence on the near-surface liquid velocity. With the increase in the spray angle, the droplets at the edge of the torch diffuse to the inclined direction, and the uniformity of the coating distribution becomes worse. Spraying height has a large influence on droplet trajectory. The coating thickness decreased significantly with the increase in spraying height, and the coating diffused in the air increased. With the increase in spraying height, the more obvious the droplet diffusion at the edge of the torch, the worse the uniformity quality of the coating. In order to ensure better spraying quality, the spraying height and angle should be controlled within a reasonable range at the same time. Spraying experiments verified the film forming law and characteristics of static spraying with gun displacement.

2005 ◽  
Vol 18 (10) ◽  
pp. 1469-1481 ◽  
Author(s):  
Glen E. Liston ◽  
Jan-Gunnar Winther

Abstract This paper presents modeled surface and subsurface melt fluxes across near-coastal Antarctica. Simulations were performed using a physical-based energy balance model developed in conjunction with detailed field measurements in a mixed snow and blue-ice area of Dronning Maud Land, Antarctica. The model was combined with a satellite-derived map of Antarctic snow and blue-ice areas, 10 yr (1991–2000) of Antarctic meteorological station data, and a high-resolution meteorological distribution model, to provide daily simulated melt values on a 1-km grid covering Antarctica. Model simulations showed that 11.8% and 21.6% of the Antarctic continent experienced surface and subsurface melt, respectively. In addition, the simulations produced 10-yr averaged subsurface meltwater production fluxes of 316.5 and 57.4 km3 yr−1 for snow-covered and blue-ice areas, respectively. The corresponding figures for surface melt were 46.0 and 2.0 km3 yr−1, respectively, thus demonstrating the dominant role of subsurface over surface meltwater production. In total, computed surface and subsurface meltwater production values equal 31 mm yr−1 if evenly distributed over all of Antarctica. While, at any given location, meltwater production rates were highest in blue-ice areas, total annual Antarctic meltwater production was highest for snow-covered areas due to its larger spatial extent. The simulations also showed higher interannual meltwater variations for surface melt than subsurface melt. Since most of the produced meltwater refreezes near where it was produced, the simulated melt has little effect on the Antarctic mass balance. However, the melt contribution is important for the surface energy balance and in modifying surface and near-surface snow and ice properties such as density and grain size.


1993 ◽  
Vol 30 (7) ◽  
pp. 1440-1452 ◽  
Author(s):  
J. A. Hole ◽  
R. M. Clowes ◽  
R. M. Ellis

As part of a multidisciplinary investigation of the structure and tectonics of the Queen Charlotte Basin and underlying crust, deep multichannel seismic reflection and coincident crustal refraction data were collected in 1988. Energy from the reflection air-gun array source was recorded at land sites at offsets appropriate to record crustal refraction and wide-angle reflection data. Refraction data recorded in a broadside geometry provide good three-dimensional coverage of western Hecate Strait. These data are modelled using tomographic inversion techniques to determine the three-dimensional velocity structure of the crust in this region. The one-dimensional average velocity increases rapidly with depth to 6.5 km/s at 7 km depth. Velocities from 7 to at least 12 km depth remain approximately constant and are associated with rocks of the Wrangellia terrane. Significant lateral velocity variations, including large differences in near-surface velocities attributable to surface features, relatively low velocities representing interbedded Tertiary sediments and volcanics, and a deep high-velocity anomaly that may represent the root of an igneous intrusion, are mapped. Wide-angle reflections from the Moho are used to determine the thickness of the crust. The Moho is at 29 km depth beneath the east coast of the Queen Charlotte Islands. This is deeper than the Moho observed below Queen Charlotte Sound and as deep as, or deeper than, that below Hecate Strait. Crustal thinning during Tertiary extension was thus greatest beneath the surface expression of the Queen Charlotte Basin, leaving the crust under the islands considerably thicker than under the basin. In an alternate or additional explanation, compression at the continental margin during the last 4 Ma may have been taken up by thickening or underplating of the continental crust beneath the islands. If the Pacific plate is subducting beneath the islands, the Moho observations constrain the slab to dip greater than 20–26°.


2021 ◽  
Vol 11 (3-S) ◽  
pp. 15-18
Author(s):  
Vipul Wayal ◽  
K. Nagasree ◽  
B. A. Vishwanath

The objective of the present study is to formulate and evaluate Silk based film forming spray for wound healing. On the wound surface the solution solidifies into a film which can deliver the active moiety on site of action. The spray solution was prepared by simple mixing of active extract of Centella Asiatica, Silk Protein and various film forming polymers. Silk protein form scaffold for active fibroblast movement and Asiaticosides from Centella Asiatica extract improve and fasten collagen synthesis. A clear yellowish solution was obtained. The formulations (F1-F8) had a pH range between 5.5–6.5, which was close to the pH of skin. The viscosity of formulation in range of 25–50 cps, completely dry film formed within 5 min in open environment. The Effects of polymers, plasticizers and solvents on spreadability. Surface tension and Spray angle were studied. The high content of ethanol in the formulation fastens the drying time. The results indicated that formulation (F8) showed good spreadability and less drying time. Keywords: Film forming spray, Wound healing, Silk protein, Asiaticoside, Scaffold


Author(s):  
M. Friis ◽  
C. Persson ◽  
J. Wigren

Abstract Plasma spraying is a very complex process, controlled by a large number of process parameters. The spray gun parameters control the plasma plume and thereby the velocity and temperature of the particles in the plasma. Some of the spray gun parameters are difficult or impossible to control, but variations of them give rise to fluctuations in the microstructure of the sprayed thermal barrier coating and thereby low reproducibility. By movement of the control from the spray gun to direct control of the particle properties in the plasma this problem will be avoided, and it should result in better process control, higher quality of the final coating and thus improved reproducibility. In this study, the influence of the plasma spray process on the coating microstructure was investigated. An orthogonal factorial designed experiment was performed, where eight process parameters were varied, resulting in 16 different coatings. The particle properties were observed in-situ with the optical measurement system DPV 2000. The microstructure of the coatings was studied using optical microscopy and the amount of different features, i.e. cracks and pores, was quantified. Multiple linear regression was used to find models describing the relation between the spray gun parameters and the particle properties, between the spray gun parameters and the microstructure, and between the particle properties and the microstructure. The results showed that the spray gun parameters well describe the variation in particle velocity and particle temperature. Further, it was found that particle velocity, particle temperature, spray angle, and substrate temperature are the most important parameters concerning influence on the coating microstructure. However, their influence on the different microstructure features varied. The study implies that focus can be set on one or two particle properties measured in the plasma, instead of the numerous spray gun parameters.


Geophysics ◽  
1983 ◽  
Vol 48 (11) ◽  
pp. 1468-1485 ◽  
Author(s):  
Dushan B. Jovanovich ◽  
Roger D. Sumner ◽  
Sharon L. Akins‐Easterlin

Detailed lithologic interpretation of seismic sections and/or pseudo‐sonic logs generated from seismic data requires that the seismic trace can be modeled as a reflection series convolved with a zero‐phase broadband wavelet. Ghosting and marine signature deconvolution processing is a prerequisite for assuring that the seismic wavelet on a marine CDP section will be zero phase. A deterministic approach to deconvolution is centered around the concept of abandoning the purely statistical method of wavelet estimation and actually measuring the seismic wavelet. A proper signature recording for marine data is, therefore, a crucial component of deterministic deconvolution. Another important element in the deterministic deconvolution sequence is the application of a deghosting filter to remove near‐surface reflections. Proper application of a deghosting filter significantly improves the correlation between log synthetics and the seismic trace. It has been found that statistical deconvolution schemes, because of the number of statistical hypotheses required to produce a deconvolution filter, produce residual wavelets that are highly variable in character and whose average phases cover the entire phase spectrum, modulo 2π. Examples of a Gulf Coast marine line which was shot with Aquapulse™, air gun, and Maxipulse™ sources by the RV Hollis Hedberg are presented to demonstrate the differences between statistical and deterministic deconvolution processing sequences. It will be shown, using sonic logs from wells adjacent to the seismic line, that the deterministic deconvolution sections for all three sources are close to zero phase while the statistical deconvolution sections have residual average phase errors between 180 and 270 degrees. The deterministic deconvolution sections have a high degree of correlation among themselves and to the wells adjacent to the line, while the statistical deconvolution sections correlate poorly to each other and to the wells. Synthetic seismograms and their impedance logs, and the seismic sections and their corresponding pseudo‐sonic logs, are used to demonstrate how deconvolution influences lithologic interpretation. ™Western Geophysics Co.


2000 ◽  
Vol 46 (154) ◽  
pp. 427-437 ◽  
Author(s):  
Jari Haapala

AbstractAn ice-thickness distribution model based on physical ice classes is formulated. Pack ice is subdivided into open water, two different types of undeformed ice, and rafted, rubble and ridged ice. Evolution equations for each ice class are formulated and a redistribution between the ice classes is calculated according to a functional form depending on the ice compactness, thickness and velocity divergence. The ice-thickness distribution model has been included in a coupled ice–ocean model, and numerical experiments have been carried out for a simulation of the Baltic Sea ice season. The extended ice classification allows separation of thermally and mechanically produced ice. Inherent thermodynamic growth/melting rates of the ice classes can be introduced into the model, giving a more detailed seasonal evolution of the pack ice. In addition, the model provides more information about the surface properties of pack ice.Numerical experiments for the Baltic Sea show that both the sub-basin and inter-basin ice characteristics were realistically simulated by the model. Deformed-ice production was related to storm activity. Most of the deformation was produced in the coastal zone, which is also an important region for thermodynamically produced ice because of the ice growth in leads. The modelled mechanical growth rates of ice were 0.5–3 cm d−1 on a basin scale, close to the thermodynamic ice-production rates. The deformed-ice fraction was 0.2 in mid-winter and increased to 0.5–1.0 during spring.


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