EFFECT OF SOLID SURFACE PROPERTY ON GEOMETRIC VARIATIONS OF MICRO- TO MILLIMETER-SIZED WATER DROPLETS DURING VOLUME REDUCTION PROCESS

2017 ◽  
Vol 27 (6) ◽  
pp. 559-568
Author(s):  
Yukihiro Yonemoto ◽  
Tomoaki Kunugi
Keyword(s):  
Solid Surface ◽  
Surface Property ◽  
Reduction Process ◽  
Volume Reduction ◽  
Water Droplets

Deformation of water droplets on solid surface in electric field

2006 ◽  
Vol 298 (2) ◽  
pp. 869-879 ◽  
Author(s):  
A. Moukengué Imano ◽  
A. Beroual
Keyword(s):  
Electric Field ◽  
Solid Surface ◽  
Water Droplets

scholarly journals Deposition of Water Droplets on the Solid Surface

1955 ◽  
Vol 8 (2) ◽  
pp. 122-127
Author(s):  
T. Uematsu ◽  
T. Kano ◽  
K. Takizawa ◽  
M. Matsuura
Keyword(s):  
Solid Surface ◽  
Water Droplets

scholarly journals Using the gravitational energy of water to generate power by separation of charge at interfaces

2015 ◽  
Vol 6 (6) ◽  
pp. 3347-3353 ◽  
Author(s):  
Yajuan Sun ◽  
Xu Huang ◽  
Siowling Soh
Keyword(s):  
Solid Surface ◽  
Gravitational Energy ◽  
Water Droplets

When water droplets (e.g., from rain) flow down a solid surface due to gravity, they can generate power.

Evaporation of Water Droplets Placed on a Heated Horizontal Surface

2002 ◽  
Vol 124 (5) ◽  
pp. 854-863 ◽  
Author(s):  
Orlando E. Ruiz ◽  
William Z. Black
Keyword(s):  
Contact Angle ◽  
Heat Conduction ◽  
Solid Surface ◽  
Fluid Motion ◽  
Surface Shape ◽  
Evaporation Process ◽  
Water Droplets ◽  
Conduction Model ◽  
Heat Conduction Model ◽  
Internal Fluid

A numerical analysis of the evaporation process of small water droplets with diameters of 1 mm or less that are gently deposited on a hot isothermal solid surface has been performed. This study considers the internal fluid motion that occurs as a result of the thermocapillary convection in the droplet and it determines the effect of fluid motion on the heat transfer between the drop and the solid surface. This study is particularly relevant because the internal fluid motion has not been considered in previous numerical and analytical models presented in the literature. To assess the effects of internal fluid motion, the model results are compared to numerical results provided by a heat conduction model that neglects the fluid motion. The Navier-Stokes and Thermal Energy equations are solved using the Artificial Compressibility Method with Dual Time Stepping. Boundary-fitted grids are used to track the changes in the droplet surface shape during the evaporation process. The numerical simulations have demonstrated that the internal fluid motion provides vastly different temperature distributions in the drop compared to the results from the heat conduction model that neglects fluid motion. The evolution of the droplet geometry was simulated from an initial spherical-shaped cap until the contact angle was close to the receding contact angle.

scholarly journals S0520201 Effect of viscoelasticity and solid surface property on liquid transfer during gravure printing

2014 ◽  
Vol 2014 (0) ◽  
pp. _S0520201--_S0520201-
Author(s):  
Jun KAGEYAMA ◽  
Takatsune NARUMI ◽  
Akiomi USHIDA ◽  
Ryuichi KAYABA
Keyword(s):  
Solid Surface ◽  
Surface Property ◽  
Gravure Printing ◽  
Liquid Transfer

scholarly journals Increasing Post-Processing Total Nucleated Cell (TNC) Recovery in Cord Blood Banking: Hespan Addition in cGMP Environment

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1126-1126
Author(s):  
Ludy Dobrila ◽  
Tracy Zhu ◽  
Dan Zamfir ◽  
Tao Wang ◽  
Michal J Tarnawski ◽  
...  
Keyword(s):  
Cord Blood ◽  
Conflicts Of Interest ◽  
Processing System ◽  
Reduction Process ◽  
Buffy Coat ◽  
Stability Study ◽  
Volume Reduction ◽  
Post Processing ◽  
Hematopoietic Stem ◽  
Cell Counts

Abstract Purpose. Evaluate the effects of HESPAN (HES) addition on indices of cord blood unit (CBU) potency, stability and safety after automated volume reduction (reduction of erythrocyte bulk and plasma volume) using the AXP AutoXpressTM (AXP) processing system. Background and Methods. TNC recovery varies significantly and unpredictably after volume reduction during CBU processing. However, prompt engraftment of CBU allotransplants correlates with their TNC including hematopoietic stem/progenitor cells (HPC). As a result, TNC is important in selecting CBU for transplantation: for example, 75% of the National Cord Blood Program (NCBP) CBUs shipped during the period 2010-2013 had TNC >120 x 107. Therefore, minimizing TNC losses during processing improves the chances that a CBU will be useful for clinical transplantation. The first method to increase post-processing TNC recovery was the addition of HES to the centrifugal method for CB volume reduction [Rubinstein et al, PNAS (USA), 92:10119-10122, 1995]. Volume reduction consists of concentrating the buffy-coat (containing leukocytes and HPC) by centrifugal stratification and removal of bulk red cells and platelet-containing plasma. NCBP processed manually over 30,000 CBUs using HES during the period 1995-2006. In 2006, the AXP, a closed, automated and FDA-approved processing method, without HES, was implemented. AXP was designed to enhance the MNC and CD34+ cell recoveries but not those of granulocytes. This resulted in lower post- processing TNC counts. Additionally, CBUs with larger volume and TNC content have somewhat higher TNC losses during automated processing. Using the AXP method, NCBP’s HEMACORD® obtained FDA License approval on November 10, 2011. However, since TNC (not MNC or CD34+ count) remains the most commonly used indicator of CBU potency and engraftment ability, we describe here implementation of HES in AXP processing to augment TNC recovery, by adding HES to the CBU to a 1-2% final concentration. Results.The results of manual CBU processing showed that HES addition improves yield, without changes in cell viability after cryopreservation, freezing at -196°C and thawing, after 20 years (from NCBP continuing stability study). HES addition also preserved CFU numbers and CD34+ cell counts after thawing. 1. Comparison of TNC recoveries without and with HES addition in the same CBU: A total of 25 CBUs were initially processed with the AXP platform without HES, as per routine procedure, and the TNC recoveries were calculated. Each CBU was then reconstituted after its initial processing into a new AXP bag set. HES was added aseptically to the reconstituted product and each CBU was processed in the same conditions as first time (same AXP device, centrifuge, etc.). The TNC recoveries after the second volume reduction process (AXP with HES) were ~20% higher on average than after the first (AXP without HES). 2. Comparison of TNC recoveries in different cohorts of CBUs: Thirty clinical-grade CBUs, with volumes 80-156 mL and TNC counts 111-290 x 107, were processed with HES in the AXP system and the results were compared with those of AXP-processed CBUs without HES over an earlier six month period. TNC and CD45+ cell recoveries improved by 16 - 20% maintaining mean post-processing hematocrit at 30.6% (SD ± 2). CD34+ and CD45+ cell viabilities were unchanged: 99% (SD ± 0.7) and 96% (SD ± 2.7), respectively, while their mean recoveries were 95% (SD ± 18) and 94% (SD ± 6). In addition, the same consistent post-processing volume was obtained (mean 20.8 mL, SD ± 0.1). CFU - CD34+ correlation (R2) after processing with HES was 0.788 (not different than what was observed in the CBUs without HES). Six CBUs AXP-processed with HES, were thawed and tested, with very minor losses in cell count and viability, similar to results of thawed AXP-processed CBU without HES. Finally, HES addition did not result in microbial contamination in any of these AXP-processed CBUs. Conclusion. Adding HES to CBUs before automated AXP processing increased substantially the TNC and CD45+ recoveries without loss of viability, while the CD34+ recoveries remained basically unchanged, with a mean of 95%. The post-processing hematocrit was consistent and low. AXP-automated CB processing with HES addition can be performed in the GMP environment, results in higher post-processing TNC and therefore, increases the CB bank’s ability to store larger CBUs that are most useful to patients. Disclosures No relevant conflicts of interest to declare.

scholarly journals Experimental Investigation on the Wind-driven Runback Motion of Water Droplets over Solid Surfaces with Different Wettabilities

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Liqun Ma ◽  
Zichen Zhang ◽  
Hui Hu
Keyword(s):  
Solid Surface ◽  
Contact Angles ◽  
Aircraft Icing ◽  
Water Droplets ◽  
Elastic Materials ◽  
Lotus Leaf ◽  
Liquid Lubricant ◽  
Measurement Results ◽  
Porous Surfaces ◽  
Ice Adhesion

Aircraft icing is widely recognized as one of the most serious weather hazards to flight safety. Specially designed hydro-/ice-phobic coatings are currently undergoing development for aircraft icing mitigation. It was found that hydro-/icephobic coatings would delay the ice accretion iover airframe surfaces so that the impacted supercooled water droplets could be blown away by the airflow from the airframe surface before being frozen into ice. It is of fundamental importance to understand the wind-driven runback behavior of water droplets over surfaces treated with different coatings, since the corresponding knowledge would be very helpful and essential to develop more efficient anti-/de-icing systems for aircraft icing protection. With the rapid development of surface engineering, a series of specially designed surface coatings succeed in icing mitigation using airflow to remove the remained water. While various hydro-/ice-phobic coatings/surfaces have been developed in recent years, the “state-of-the-art” icephobic coatings/surfaces can be generally divided into three categories, i.e., 1). Lotus-leaf-inspired superhydrophobic surfaces (SHS) with micro-/nano-scale surface textures to achieve very high contact angles (typically > 150°); 2). Pitcherplant-inspired slippery liquid infused porous surfaces (SLIPS) with a layer of liquid lubricant (which is immiscible with water) being sandwiched between ice and solid substrate materials; and 3). Icephobic elastic materials/surfaces with deformable structures/surfaces. SHS has a water droplet contact angle (CA) larger than 150° and a sliding angle (SA) less than 10° . SHS always has a hierarchical structure which is similar to the lotus leaf, and water droplets on SHS appear as water beads which can easily roll off the surface by wind or gravity before frozen. Another strategy to reduce ice adhesion strength to a solid surface is to use a layer of liquid lubricant, which is immiscible with water, between ice and the solid surface. The use of such lubricated surfaces was investigated as early as 1960s, and has gained increasing attentions again recently with the introduction of a concept called Slippery Liquid-Infused Porous Surfaces (SLIPS). SLIPS concept is inspired by the Nepenthes pitcher plants, which have evolved highly slippery, liquidinfused micro-textured rim to capture insects. SLIPS surfaces were not only found to be able to suppress ice/frost accretion by effectively removing condensed moisture even in high humidity conditions, but also exhibit at least an order of magnitude lower ice adhesion than most SHS coatings. More recently, elastic materials/surfaces, such as Polydimethylsiloxane or PDMS in short, which would be structurally deformed/altered dynamically upon applying extra mechanical stress, have also been suggested for icing mitigation. Elastic materials display ultra-low adhesion to ice due to their low work of adhesion and liquidlike deformability, while maintaining good mechanical durability due to their solid-like rigidity. It is found that water droplets would not only be more readily rebounding away from the surface after impingement, but also be able to roll away before frozen due to the hydrophobicity of PDMS. Considering the differences in wettabilities and mechanisms of water repellency, it is necessary to have a systematic understanding of how efficient the surfaces are when the aerodynamic force is applied to remove the adhered water droplets. In the present study, a comprehensive experimental campaign was conducted to characterize the transient runback behaviors of wind-driven water droplets over the surfaces of test plates coated with different hydro-/icephobic coatings (i.e., SHS, SLIPS and PDMS). A high-resolution Particle Image Velocimetry (PIV) system was used to achieve quantitative measurements of the velocity field of the airflow around the wind-driven water droplets on the test surfaces with different wettabilities. With the detailed PIV measurements of the airflow field around the runback water droplets and the droplet profiles, the aerodynamic forces and the adhesion forces acting on the water droplets were estimated. While Fig. 1 shows the experimental setup used in the present study, Fig. 2 to Fig. 3 given some of the typical measurement results. More measurement results and comprehensive analysis and discussions will be provided in the full version of this research paper.

scholarly journals Deposition of Water Droplets on the Solid Surface

1956 ◽  
Vol 2 (1) ◽  
pp. 49-50
Author(s):  
Tokio Uematu ◽  
Takesi Kano ◽  
Kazuhiro Takizawa ◽  
Masami Matuura
Keyword(s):  
Solid Surface ◽  
Water Droplets

Interaction phenomena of two water droplets successively impacting onto a solid surface

2008 ◽  
Vol 47 (3) ◽  
pp. 229-236 ◽  
Author(s):  
Hitoshi Fujimoto ◽  
Albert Y. Tong ◽  
Hirohiko Takuda
Keyword(s):  
Solid Surface ◽  
Water Droplets ◽  
Interaction Phenomena
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