3D printed triply periodic minimal surfaces as spacers for enhanced heat and mass transfer in membrane distillation

Desalination ◽  
2018 ◽  
Vol 443 ◽  
pp. 256-271 ◽  
Author(s):  
Navya Thomas ◽  
Nurshaun Sreedhar ◽  
Oraib Al-Ketan ◽  
Reza Rowshan ◽  
Rashid K. Abu Al-Rub ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Minimal Surfaces ◽  
Membrane Distillation ◽  
Triply Periodic Minimal Surfaces ◽  
Triply Periodic ◽  
3D Printed

scholarly journals Porous polylactic acid scaffolds for bone regeneration: A study of additively manufactured triply periodic minimal surfaces and their osteogenic potential

2020 ◽  
Vol 11 ◽  
pp. 204173142095654
Author(s):  
Anna Diez-Escudero ◽  
Hugo Harlin ◽  
Per Isaksson ◽  
Cecilia Persson
Keyword(s):  
Polylactic Acid ◽  
Cancellous Bone ◽  
Minimal Surfaces ◽  
Pore Distribution ◽  
Osteogenic Potential ◽  
Osteoblastic Cell ◽  
Triply Periodic Minimal Surfaces ◽  
Triply Periodic ◽  
3D Printed ◽  
Grade Material

Three different triply periodic minimal surfaces (TPMS) with three levels of porosity within those of cancellous bone were investigated as potential bone scaffolds. TPMS have emerged as potential designs to resemble the complex mechanical and mass transport properties of bone. Diamond, Schwarz, and Gyroid structures were 3D printed in polylactic acid, a resorbable medical grade material. The 3D printed structures were investigated for printing feasibility, and assessed by morphometric studies. Mechanical properties and permeability investigations resulted in similar values to cancellous bone. The morphometric analyses showed three different patterns of pore distribution: mono-, bi-, and multimodal pores. Subsequently, biological activity investigated with pre-osteoblastic cell lines showed no signs of cytotoxicity, and the scaffolds supported cell proliferation up to 3 weeks. Cell differentiation investigated by alkaline phosphatase showed an improvement for higher porosities and multimodal pore distributions, suggesting a higher dependency on pore distribution and size than the level of interconnectivity.

3D printed feed spacers based on triply periodic minimal surfaces for flux enhancement and biofouling mitigation in RO and UF

Desalination ◽  
2018 ◽  
Vol 425 ◽  
pp. 12-21 ◽  
Author(s):  
Nurshaun Sreedhar ◽  
Navya Thomas ◽  
Oraib Al-Ketan ◽  
Reza Rowshan ◽  
Hector Hernandez ◽  
...  
Keyword(s):  
Minimal Surfaces ◽  
Flux Enhancement ◽  
Triply Periodic Minimal Surfaces ◽  
Triply Periodic ◽  
3D Printed

Mass transfer analysis of ultrafiltration using spacers based on triply periodic minimal surfaces: Effects of spacer design, directionality and voidage

2018 ◽  
Vol 561 ◽  
pp. 89-98 ◽  
Author(s):  
Nurshaun Sreedhar ◽  
Navya Thomas ◽  
Oraib Al-Ketan ◽  
Reza Rowshan ◽  
Hector H. Hernandez ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Minimal Surfaces ◽  
Triply Periodic Minimal Surfaces ◽  
Triply Periodic

scholarly journals Development of mass and heat transfer coupled model of hollow fiber membrane for salt recovery from brine via osmotic membrane distillation

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Sher Ahmad ◽  
Gabriela Vollet Marson ◽  
Waheed Ur Rehman ◽  
Mohammad Younas ◽  
Sarah Farrukh ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Heat And Mass Transfer ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Membrane Distillation ◽  
Fiber Membrane ◽  
Salt Recovery ◽  
Osmotic Solution

Abstract Background In this research work, a coupled heat and mass transfer model was developed for salt recovery from concentrated brine water through an osmotic membrane distillation (OMD) process in a hollow fiber membrane contactor (HFMC).The model was built based on the resistance-in-series concept for water transport across the hydrophobic membrane. The model was adopted to incorporate the effects of polarization layers such as temperature and concentration polarization, as well as viscosity changes during concentration. Results The modeling equations were numerically simulated in MATLAB® and were successfully validated with experimental data from literature with a deviation within the range of 1–5%. The model was then applied to study the effects of key process parameters like feed concentrations, osmotic solution concentration, feed, and osmotic solution flow rates and feed temperature on the overall heat and mass transfer coefficient as well as on water transport flux to improve the process efficiency. The mass balance modeling was applied to calculate the membrane area based on the simulated mass transfer coefficient. Finally, a scale-up for the MD process for salt recovery on an industrial scale was proposed. Conclusions This study highlights the effect of key parameters for salt recovery from wastewater using the membrane distillation process. Further, the applicability of the OMD process for salt recovery on large scale was investigated. Sensitivity analysis was performed to identify the key parameters. From the results of this study, it is concluded that the OMD process can be promising in salt recovery from wastewater.

Description of a 3-periodic minimal surface family with trigonal symmetry

1994 ◽  
Vol 209 (1) ◽  
Author(s):  
A. Fogden
Keyword(s):  
Minimal Surface ◽  
Minimal Surfaces ◽  
Weierstrass Representation ◽  
Systematic Analysis ◽  
Trigonal Symmetry ◽  
Triply Periodic Minimal Surfaces ◽  
Periodic Minimal Surface ◽  
Triply Periodic ◽  
The Family

AbstractA systematic analysis of a family of triply periodic minimal surfaces of genus seven and trigonal symmetry is given. The family is found to contain five such surfaces free from self-intersections, three of which are previously unknown. Exact parametrisations of all surfaces are provided using the Weierstrass representation.

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