scholarly journals Nanograined surface shell wall controlled ZnO–ZnS core–shell nanofibers and their shell wall thickness dependent visible photocatalytic properties

2017 ◽  
Vol 7 (5) ◽  
pp. 1167-1180 ◽  
Author(s):  
Kuglaur Shanmugam Ranjith ◽  
Anitha Senthamizhan ◽  
Brabu Balusamy ◽  
Tamer Uyar
Keyword(s):  
Wall Thickness ◽  
Photocatalytic Properties ◽  
Core Shell ◽  
Shell Wall ◽  
Shell Form ◽  
The Core ◽  
Surface Shell ◽  
Visible Irradiation ◽  
Shell Wall Thickness

The core–shell form of ZnO–ZnS based heterostructural nanofibers (NF) has received increased attention for use as a photocatalyst owing to its potential for outstanding performance under visible irradiation.

Effective shell wall thickness of vertically aligned ZnO-ZnS core-shell nanorod arrays on visible photocatalytic and photo sensing properties

2018 ◽  
Vol 237 ◽  
pp. 128-139 ◽  
Author(s):  
Kugalur Shanmugam Ranjith ◽  
Rutely Burgos Castillo ◽  
Mika Sillanpaa ◽  
Ramasamy Thangavelu Rajendra Kumar
Keyword(s):  
Wall Thickness ◽  
Core Shell ◽  
Nanorod Arrays ◽  
Shell Wall ◽  
Sensing Properties ◽  
Vertically Aligned ◽  
Shell Wall Thickness

scholarly journals A Bayesian Approach for Estimating the Thinning Corrosion Rate of Steel Heat Exchanger in Hydrodesulfurization Plants

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
J. C. Velázquez ◽  
F. Caleyo ◽  
R. Cabrera-Sierra ◽  
G. Teran ◽  
E. Hernandez-Sanchez ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Heat Exchangers ◽  
Jet Fuel ◽  
Statistical Techniques ◽  
Shell Wall ◽  
Oil Refineries ◽  
Bayesian Data Analysis ◽  
Thinning Rate ◽  
Shell Wall Thickness ◽  
Steel Heat

Fuel consumption has been increasing in recent years, especially that of diesel and jet fuel. For this reason, the necessity to build new plants to reduce their sulfur content has arisen. Sometimes, just revamping existing plants is feasible, but determining which pieces of equipment are in the appropriate condition to be reused is also necessary. In order to select the equipment, it is essential to have information about the wall thickness of vessels. Sometimes, the information is limited; consequently, the application of advanced statistical techniques is needed. The Bayesian Data Analysis (BDA) used in this study has the goal of determining a more accurate, unobserved thinning rate distribution for existing heat exchangers, taking into consideration all the information available about the thinning rate of the heat exchangers that cool down the effluent of the hydrotreating reactors in Mexican oil refineries. The information obtained from BDA was compared with existing shell wall thickness obtaining favorable results.

Robocasting of carbon-alumina core-shell composites using co-extrusion

2017 ◽  
Vol 23 (2) ◽  
pp. 423-433 ◽  
Author(s):  
Zongwen Fu ◽  
Matthias Freihart ◽  
Tobias Schlordt ◽  
Tobias Fey ◽  
Torsten Kraft ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Wall Thickness ◽  
Extrusion Process ◽  
Truss Structures ◽  
Core Shell ◽  
Lattice Structures ◽  
Content Type ◽  
The Core ◽  
Alumina Gels ◽  
Carbon Core

Purpose This study aims to achieve the fabrication of three-dimensional core-shell filament-based lattice structures by means of robocasting combined with co-extrusion. For core and shell materials, colloidal gels composed of submicron carbon and alumina powders were developed, respectively. Simultaneously, the co-extrusion process was also studied by numerical simulation to investigate the feed pressure-dependent wall thickness. Design/methodology/approach Significant differences in the rheological behavior of the carbon and alumina gels were observed because of differences of the particle morphology and surface chemistry of the carbon and alumina powders. Precise control over the cross-sectional diameter of the core and shell green state elements was achieved by alteration of the feed pressures used during co-extrusion. Findings After subsequent thermal treatment in an oxidizing atmosphere (e.g. air), in which the carbon core was oxidized and burned out, lattice structures formed of hollow filaments of predetermined wall thickness were manufactured; additionally, C-Al2O3 core-shell filament lattice structures could be derived after firing in an argon atmosphere. Originality/value Green lattice truss structures with carbon core and alumina shell filaments were successfully manufactured by robotically controlled co-extrusion. As feedstocks carbon and alumina gels with significantly different rheological properties were prepared. During co-extrusion, the core paste exhibited a much higher viscosity than the shell paste, which benefited the co-extrusion process. Simultaneously, the core and shell diameters were exactly controlled by core and shell feed pressures and studied by numerical simulation. The experimentally and numerically derived filament wall thickness showed qualitative agreement with each other; with decreasing core pressure during co-extrusion, the wall thickness increased.

Comparison of Hybrid Rapid Mouldings for Zinc Alloy Castings

2011 ◽  
Vol 110-116 ◽  
pp. 653-659
Author(s):  
Rupinder Singh
Keyword(s):  
Mechanical Properties ◽  
Wall Thickness ◽  
Three Dimensional ◽  
Dimensional Accuracy ◽  
Zinc Alloy ◽  
Shell Wall ◽  
Permissible Range ◽  
Alloy Castings ◽  
Zn Alloy ◽  
Shell Wall Thickness

In this work comparison of hybrid rapid moulds (prepared with three dimensional printing shells supported with dry, green and molasses sand) have been made for techno-economic analysis, for zinc (Zn) alloy shell casting. The comparison has been made on the basis of mechanical properties and dimensional accuracy. Time-temperature curves have been drawn to understand solidification of molten Zn alloy in hybrid moulds of different thicknesses. The results of study suggest that it is feasible to reduce shell wall thickness of hybrid mould cavity from recommended 12mm to 1mm. All castings prepared are consistent with the permissible range of IT grades and are acceptable as per ISO standard UNI EN 20286-1 (1995). Further green sand based hybrid prototypes at 3mm shell wall thickness, shows better dimensional accuracy and mechanical properties.

scholarly journals Modeling the impact of shell wall thickness thinning on the stress state

2021 ◽  
Vol 1889 (4) ◽  
pp. 042089
Author(s):  
Karina Abdrakhmanova ◽  
Evgeniy Yarmonov ◽  
Petr Kulakov ◽  
Rezeda Tlyasheva
Keyword(s):  
Stress State ◽  
Wall Thickness ◽  
Shell Wall ◽  
The Impact ◽  
Shell Wall Thickness

Modeling of Dimensional Accuracy in Three Dimensional Printing for Light Alloy Casting

2014 ◽  
Vol 808 ◽  
pp. 65-78
Author(s):  
Rajesh Kumar ◽  
Rupinder Singh ◽  
Inderpreet Singh Ahuja
Keyword(s):  
Wall Thickness ◽  
Three Dimensional ◽  
Dimensional Accuracy ◽  
Outer Diameter ◽  
Shell Wall ◽  
Light Alloy ◽  
Three Dimensional Printing ◽  
Measuring Machine ◽  
Dimensional Printing ◽  
Shell Wall Thickness

The purpose of this paper is to develop mathematical model to investigate the influence of shell casting parameters. Three input parameters such as shell wall thickness (SWT), Pouring temperature (PT) and weight density (WD) were selected to give output in the form of average outer diameter (AOD) as dimensional accuracy. After identification of component, technological prototypes were produced. In this work three dimensional printing (3DP) has been used as rapid shell casting to make shell mould by using Zcast 501 powder with different shell wall thickness for six different light alloy materials. Measurements on a coordinate-measuring machine helped in calculating the dimensional tolerances of the castings produced. For obtaining tight casting tolerances the dimensional accuracy of component is the most important element. The thickness, curing time and orientation of the shell molds, play an important role in providing a high quality of the cast part in time. The dimensional accuracy was found to be more in the case of maximum layer thickness and horizontal position of the component. The investigation has led to conclusions as the Quadratic models were developed for the response. The F - value is 23.93, which implies that the model as well as lack of fit is significant. The value of Prob > F is less then the standard value 0.05, which indicates model terms are significant. With the help of Post curing, shell Mold temperature was not found to affect the dimensional accuracy of the castings, significantly. It was observed that high pouring temperatures also produced castings with better dimensional accuracy. This study will provide main effect of the inputs on average outer diameter as dimensional accuracy in three dimensional printing of light alloys castings. Statistically in this case B, C, A2, B2, C2, AB, BC is the model terms which contributes significantly to the model developed for dimensional accuracy.

Effect of Work Piece Dimensions on Cost Effective Hybrid Rapid Casting Solution for Aluminium Alloy

2011 ◽  
Vol 264-265 ◽  
pp. 397-402
Author(s):  
Rupinder Singh ◽  
Rupinder Singh
Keyword(s):  
Aluminum Alloy ◽  
Wall Thickness ◽  
Cost Effective ◽  
Work Piece ◽  
Shell Wall ◽  
Rapid Casting ◽  
Casting Solution ◽  
Volume Weight ◽  
Mould Cavity ◽  
Shell Wall Thickness

The purpose of the present experimental investigations is to study the effect of work piece dimensions on reducing the shell wall thickness of mould cavity for cost effective, hybrid rapid casting solution of aluminum alloy. Starting from the identification of component/benchmark, technological prototypes with three different work piece dimensions (volume/ weight) were produced, at different shell wall thickness of mould cavity using hybrid rapid prototyping technique (combination of three dimensional printing and conventional sand casting). Measurements on the coordinate measuring machine helped in calculating the dimensional tolerances of the castings produced. Some important mechanical properties were also compared to verify the suitability of the castings. The study suggested that the shell wall thickness, having value less than the recommended one is more suitable from dimensional accuracy and economic point of view, for all three work piece dimensions (volume/ weight). Further best shell wall thickness of the mould cavity for different work piece dimensions of the selected benchmark has been highlighted for rapid casting solution of aluminum alloy.

Effect of Moulding Sand Properties on Cost Effective Hybrid Rapid Casting Solution for Zinc Alloy

2011 ◽  
Vol 264-265 ◽  
pp. 1637-1642
Author(s):  
Rupinder Singh ◽  
T. Lal
Keyword(s):  
Wall Thickness ◽  
Cost Effective ◽  
Zinc Alloy ◽  
Shell Wall ◽  
Rapid Casting ◽  
Casting Solution ◽  
Mould Cavity ◽  
Measuring Machine ◽  
Moulding Sand ◽  
Shell Wall Thickness

The purpose of the present experimental investigations is to study the effect of moulding sand properties on reducing the shell wall thickness of mould cavity for cost effective, hybrid rapid casting solution of zinc alloy. Starting from the identification of component/benchmark, technological prototypes were produced, with three different moulding sands (dry, green and molasses), at different shell wall thickness of mould cavity using hybrid rapid prototyping technique (combination of three dimensional printing and conventional sand casting). Measurements on the coordinate measuring machine helped in calculating the dimensional tolerances of the castings produced. Some important mechanical properties were also compared to verify the suitability of the castings. The study suggested that for the shell thickness, having value less than the recommended one is more suitable from dimensional accuracy and economic point of view, for all three moulding sands. Further best shell wall thickness of the mould cavity for different moulding sands, for the selected component/benchmark has been highlighted for rapid casting solution of zinc alloy.

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