HOT WATER-REPELLENT SUPERHYDROPHOBIC SURFACES WITH LONG-TERM STABILITY

2021 ◽  
Author(s):  
JI SEONG CHOI ◽  
SEONG MIN KANG
Keyword(s):  
Hot Water ◽  
Superhydrophobic Surfaces ◽  
Water Repellent ◽  
Water Droplets ◽  
Long Term Stability ◽  
Cassie State ◽  
Potential Applications ◽  
Different Temperatures ◽  
Temperature Water

In this paper, we fabricate and evaluate superhydrophobic surfaces with mushroom-shaped microstructures. Using a silicon master and polymer microstructure patterning, polydimethylsiloxane (PDMS) surfaces bearing mushroom-shaped structures with five different spacing ratios are prepared and tested with water droplets of different temperatures. The fabricated PDMS surfaces demonstrate superhydrophobicity even to high-temperature water droplets with decreased surface tension. We compare the experimental data with the theoretical results calculated based on the Cassie state and Eötvös rule. Our work suggests potential applications to control wettability with liquids of various temperatures.

Water repellent room temperature vulcanized silicone for enhancing the long-term stability of perovskite solar cells

Solar Energy ◽  
2021 ◽  
Vol 218 ◽  
pp. 28-34
Author(s):  
Mahmoud Samadpour ◽  
Mahsa Heydari ◽  
Mahdi Mohammadi ◽  
Parisa Parand ◽  
Nima Taghavinia
Keyword(s):  
Solar Cells ◽  
Room Temperature ◽  
Perovskite Solar Cells ◽  
Water Repellent ◽  
Term Stability ◽  
Long Term Stability

Evaluation of long-term frozen storage of plasma for measurement of high-density lipoprotein and its subfractions by precipitation

1990 ◽  
Vol 36 (5) ◽  
pp. 783-788 ◽  
Author(s):  
M N Nanjee ◽  
N E Miller
Keyword(s):  
High Density Lipoprotein ◽  
Liquid Nitrogen ◽  
Frozen Storage ◽  
Density Lipoprotein ◽  
High Density ◽  
Long Term Stability ◽  
Long Term Storage ◽  
Different Temperatures ◽  
Edta Plasma

Abstract The concentration of high-density lipoprotein cholesterol (HDL-C) in plasma is now established as an independent risk factor for coronary heart disease, but more data are needed on the relative risk-predictive powers of different HDL subclasses. For epidemiologic and clinical purposes, isolation of HDL from other lipoproteins and separation of its two major subclasses, HDL2 and HDL3, are performed most conveniently by precipitation. Although storage of plasma is commonly necessary, little information is available on the long-term stability of HDL subclasses at different temperatures. Therefore, we quantified HDL-C, HDL2-C, and HDL3-C by dual precipitation with heparin-MnCl2/15-kDa dextran sulfate (H-M/DS) in samples of EDTA-plasma from 93 healthy subjects, after storage for one to 433 days at -20 degrees C, at -70 degrees C, or in liquid nitrogen (-196 degrees C). Fourteen samples (15%) were stored for a year or longer. At -20 degrees C, HDL-C decreased by 4.8% per year and HDL3-C decreased by 6.9% per year (P = 0.002 for both variables) relative to results obtained with samples stored in liquid nitrogen; total cholesterol, HDL2-C, and triglyceride did not change significantly at this temperature. When stored at -70 degrees C, none of the lipids showed any change relative to results obtained with liquid nitrogen. Thus, long-term storage of EDTA-plasma at -20 degrees C is unsuitable for subsequent quantification of HDL-C and its subclasses by H-M/DS dual precipitation. Storage at -70 degrees C is preferable, and is as reliable as storage in liquid nitrogen.

scholarly journals Light Yield Response of Neutron Scintillation Screens to Sudden Flux Changes

2020 ◽  
Vol 6 (12) ◽  
pp. 134
Author(s):  
Tobias Neuwirth ◽  
Bernhard Walfort ◽  
Simon Sebold ◽  
Michael Schulz
Keyword(s):  
Neutron Flux ◽  
Light Yield ◽  
Neutron Imaging ◽  
Frame Rate ◽  
Yield Response ◽  
High Frame Rate ◽  
Long Term Stability ◽  
High Light Yield ◽  
Different Temperatures

We performed a study of the initial and long term light yield of different scintillation screen mixtures for neutron imaging during constant neutron irradiation. We evaluated the light yield during different neutron flux levels as well as at different temperatures. As high frame rate imaging is a topic of interest in the neutron imaging community, the decay characteristics of scintillation screens are of interest as well. Hence, we also present and discuss the decay behavior of the different scintillation screen mixtures on a time scale of seconds. We have found that the decay time of ZnS:Cu/6LiF excited with a high neutron flux is potentially much longer than typically stated. While most of the tested scintillation screens do not provide a significant improvement over currently used scintillation screen materials, Zn(Cd)S:Ag/6LiF seems to be a good candidate for high frame rate imaging due to its high light yield, long-term stability as well as fast decay compared to the other evaluated scintillation screens.

scholarly journals Superhydrophobic surfaces

2012 ◽  
Vol 21 (1-2) ◽  
pp. 21-32 ◽  
Author(s):  
Ioannis Karapanagiotis ◽  
Panagiotis Manoudis
Keyword(s):  
Water Repellency ◽  
Superhydrophobic Surfaces ◽  
Water Repellent ◽  
Baxter Equation ◽  
Feature Article ◽  
Surface Protection ◽  
Recent Developments ◽  
Potential Applications ◽  
Nanoparticle Composites ◽  
Potential Use

AbstractSuperhydrophobicity – also known as water repellency – has recently attracted considerable attention because of its numerous potential applications. However, the fundamental concepts and equations describing the wettability of superhydrophobic surfaces have been known since the 1940s. These concepts are reviewed and discussed in the present feature article in light of the recent developments. Furthermore, the potential use of water-repellent siloxane-nanoparticle composites for surface protection and consolidation of stones and mortars used in outdoor objects of cultural heritage is investigated. Finally, it is shown that the wettability of the composite surfaces can be predicted by the Cassie-Baxter equation.

A Novel Water-Based Drilling Fluid Tailored for Challenging Slanted HTHP Wells

2021 ◽  
Author(s):  
Vaughn Reza Traboulay ◽  
Tint Htoo Aung ◽  
Cedric Manzoleloua ◽  
Balakrishnan Panamarathupalayam ◽  
Carmelo Arena ◽  
...  
Keyword(s):  
High Temperature ◽  
Drilling Fluid ◽  
Synthetic Polymer ◽  
Term Stability ◽  
Long Term Stability ◽  
High Temperature Water ◽  
Water Based ◽  
Static Conditions ◽  
Temperature Water

Abstract High-temperature water-based drilling fluid systems hold several advantages over synthetic based systems from financial and environmental viewpoints. However, most conventional water-based systems start to become unstable at temperatures above 300 degF. This paper details the design and implementation of A Novel Water-Based Drilling Fluid that meet these temperature stability requirements. The newly developed high-temperature water-based system discussed in this paper utilizes a custom-made branched synthetic polymer that exhibits superior rheological properties and fluid loss control as well as long term stability above 400 degF. The branched synthetic polymer is compatible with most oilfield brines and maintains excellent low-end rheology necessary for hole cleaning and solids suspension under high-temperatures and pressures. Under static conditions, the high-temperature fluid shows no gelation resulting in lower swab surge pressures while the stability of the highly branched synthetic polymer and enhanced rheological profile minimize sag. To drill a challenging exploration well, a Middle East client required a cost-effective drilling fluid system which remains stable under static temperatures expected to exceed 375 degF. The long-term stability of the system was critical for successful wireline logging operations. In addition, the system was required to provide shale inhibition, hydrogen sulfide suppression and sufficient density (above 16.5 lbm/galUS) to maintain well integrity while drilling through anticipated high-pressure zones. The challenging intermediate (12.25-in and 8.375-in) and reservoir (6-in) sections were successfully drilled and evaluated using this new branched synthetic polymer-based system. Fluid property trends and system treatments will be detailed alongside thermal stability data for extended periods required for wireline logging (up to 9 days static). This paper will discuss how proper laboratory design of the high-temperature water-based system was translated to excellent field performance and will indicate how this technology can be utilized for future campaigns in the region and worldwide.

scholarly journals The Role of Pitch and Tempo in Sound-Temperature Crossmodal Correspondences

2017 ◽  
Vol 30 (3-5) ◽  
pp. 307-320 ◽  
Author(s):  
Qian (Janice) Wang ◽  
Charles Spence
Keyword(s):  
Room Temperature ◽  
Cold Water ◽  
Hot Water ◽  
Crossmodal Correspondences ◽  
Online Study ◽  
Fast Tempo ◽  
Potential Applications ◽  
Different Levels ◽  
Temperature Water

We explored the putative existence of crossmodal correspondences between sound attributes and beverage temperature. An online pre-study was conducted first, in order to determine whether people would associate the auditory parameters of pitch and tempo with different imagined beverage temperatures. The same melody was manipulated to create a matrix of 25 variants with five different levels of both pitch and tempo. The participants were instructed to imagine consuming hot, room-temperature, or cold water, then to choose the melody that best matched the imagined drinking experience. The results revealed that imagining drinking cold water was associated with a significantly higher pitch than drinking both room-temperature and hot water, and with significantly faster tempo than room-temperature water. Next, the online study was replicated with participants in the lab tasting samples of hot, room-temperature, and cold water while choosing a melody that best matched the actual tasting experience. The results confirmed that, compared to room-temperature and hot water, the experience of cold water was associated with both significantly higher pitch and fast tempo. Possible mechanisms and potential applications of these results are discussed.

Study on Water Plugging Technology by Emulsified Viscous Oil in Block Jin16

2014 ◽  
Vol 535 ◽  
pp. 432-435
Author(s):  
Fu Dong Sui ◽  
Guang Sheng Cao ◽  
Chun Bao Ma ◽  
Xiao Ma
Keyword(s):  
Crude Oil ◽  
Advanced Technology ◽  
Long Term Stability ◽  
Viscous Oil ◽  
Sealing Performance ◽  
Effects Of Temperature ◽  
Core Simulation ◽  
Stability Of Emulsion ◽  
Temperature Water

Water plugging by emulsified viscous oil s a kind of advanced technology with high selectivity, which causes little damage to reservoir and brings high economic benefit for oil wells. Through a series of simulation experiments in the laboratory, the effects of temperature, water ratio, salinity, the emulsifier concentration, the viscosity of crude oil on the emulsion viscosity is studied, also long-term stability of emulsion. The following analysis of the experimental data makes the main factor affecting water plugging by emulsified heavy oil clear. By the Indoor core simulation experiment, this paper determines changes of pressure, recovery and breakthrough pressure and studies injection capacity of emulsified crude oil and sealing performance to ensure reasonable injection parameters.

scholarly journals Development and Analysis of Long-Term Measurement Systems for Groundwater Level Using Electric Capacity

2021 ◽  
Vol 21 (6) ◽  
pp. 227-237
Author(s):  
Seok-Ju Kim ◽  
Do-Kyun Kim
Keyword(s):  
Groundwater Level ◽  
Measuring Equipment ◽  
Measurement Data ◽  
Underground Water ◽  
The Body ◽  
Water Repellent ◽  
Long Term Stability ◽  
Electric Capacity ◽  
Long Term Measurement

In soil dams and embankments made of soil, deterioration and stress release owing to internal and external influences occur, and the instability of the body increases as the shear strength decreases. In particular, understanding the location and flow of underground water is very important for securing the long-term stability of waterfront structures in contact with water. However, the physical limitations of measuring equipment cause many difficulties in understanding the existence and location of groundwater over a long period of time. In this study, measuring equipment using electric capacity was developed for the long-term measurement of groundwater, and contactless measuring sensors were manufactured to eliminate the possibility of corrosion by water. In addition, the precision of the measurement data was improved by applying waterproof and water-repellent coatings to the measurement sensor. Laboratory tests conducted using the developed equipment demonstrate the high precision of the measurement data according to the groundwater level change and enhanced durability of the sensor, which facilitate long-term measurements in the field.

scholarly journals Gas discrimination by simultaneous sound velocity and attenuation measurements using uncoated capacitive micromachined ultrasonic transducers

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Luis Iglesias Hernandez ◽  
Priyadarshini Shanmugam ◽  
Jean-François Michaud ◽  
Daniel Alquier ◽  
Dominique Certon ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Ultrasonic Transducers ◽  
Multiple Reflections ◽  
Nuclear Waste Storage ◽  
Capacitive Micromachined Ultrasonic Transducers ◽  
Long Term Stability ◽  
Waste Storage ◽  
Potential Applications ◽  
Hazardous Gases

AbstractChemically functionalized or coated sensors are by far the most employed solution in gas sensing. However, their poor long term stability represents a concern in applications dealing with hazardous gases. Uncoated sensors are durable but their selectivity is poor or non-existent. In this study, multi-parametric discrimination is used as an alternative to selectivity for uncoated capacitive micromachined ultrasonic transducers (CMUTs). This paper shows how measuring simultaneously the attenuation coefficient and the time of flight under different nitrogen mixtures allows to identify hydrogen, carbon dioxide and methane from each other and determine their concentration along with identification of temperature and humidity drifts. Theoretical comparison and specific signal processing to deal with the issue of multiple reflections are also presented. Some potential applications are monitoring of refueling stations, vehicles and nuclear waste storage facilities.

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