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.

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

scholarly journals Sundew-Inspired Adhesive Hydrogel Threads through Reversible Complexation of Polyphenol and Boronic Acid

2021 ◽  
Vol 11 (18) ◽  
pp. 8591
Author(s):  
Jae Hyuk Choi ◽  
Donghee Son ◽  
Mikyung Shin
Keyword(s):  
Boronic Acid ◽  
Skin Wound ◽  
Body Fluids ◽  
The Body ◽  
Wound Dressings ◽  
Suture Materials ◽  
Wound Site ◽  
Long Term Stability ◽  
State Dependent

Adhesive hydrogels have been utilized as tissue sealants, hemostatic agents, and wound dressings, with the aim of replacing conventional sutures. To prevent immune response and serious inflammation from those hydrogels after sealing, natural biocompatible polysaccharides are widely used as a component of the hydrogels. However, the weak mechanical strength, insufficient adhesiveness, and rapid dissociation of the hydrogels necessitates additional suturing at the wound site. In this study, we report on a solid polysaccharide thread reversibly crosslinked with boronic acid-polyphenol complexation and its adhesive gelation for complete tissue sealing without additional suturing. The polysaccharide adhesive suture threads demonstrated long-term stability, which is useful when used for skin wound suturing. Specifically, their robust adhesion property occurred as soon as the threads were soaked, attaining a swollen hydrogel state, dependent on the presence of body fluids after suturing. Moreover, the pH of the body fluids affects the viscoelasticity and adhesiveness of the hydrogels in order to ensure a tight sealing. Therefore, we expect that these pH-responsive adhesive threads would be promising for the development of on-demand functional suture materials.

Modifying Brushite Cement Degradation Using Calcium Alginate Beads

2007 ◽  
Vol 361-363 ◽  
pp. 311-314 ◽  
Author(s):  
Liam M. Grover ◽  
Sarika Patel ◽  
Y. Hu ◽  
Uwe Gbureck ◽  
J.E. Barralet
Keyword(s):  
Calcium Alginate ◽  
Alginate Beads ◽  
The Body ◽  
Cement Matrix ◽  
Calcium Alginate Beads ◽  
Long Term Stability ◽  
The Matrix ◽  
Implant Degradation

The hydrolysis of brushite in calcium phosphate cements to form hydroxyapatite is known to result in the long term stability of the material in the body. It has previously been established that this hydrolysis reaction can be influenced by implant volume, media refreshment rate and media composition. In this study, the effect of macroporosity on the rate of degradation of the material is investigated. Macroporosity was incorporated into the material using calcium alginate beads mixed into the cement paste. The inclusion of the calcium alginate beads did not influence the degree of conversion of the material and allowed the incorporation of porosity at up to maximum of 57%. The macroporosity weakened the cement matrix (from 46.5 to 3.2 MPa). When aged the brushite in the macroporous cement dissolved completely from the matrix resulting in a weight loss of 60wt% in a period of 28 days. This suggests that the controlled incorporation of calcium alginate beads into brushite cements in vivo can be used to control implant degradation rate.

Vertical distribution of greenhouse gases above Western Siberia by the long-term measurement data

2009 ◽  
Vol 22 (3) ◽  
pp. 316-324 ◽  
Author(s):  
M. Yu. Arshinov ◽  
B. D. Belan ◽  
D. K. Davydov ◽  
G. Inouye ◽  
Sh. Maksyutov ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Greenhouse Gases ◽  
Western Siberia ◽  
Measurement Data ◽  
Long Term Measurement

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.

scholarly journals Study of Trends in Concentrations of Basic Air Pollutants in the Malopolska Province

2020 ◽  
Vol 27 (4) ◽  
pp. 567-578
Author(s):  
Mariusz Filak ◽  
Szymon Hoffman
Keyword(s):  
Air Quality ◽  
Environmental Protection ◽  
Tropospheric Ozone ◽  
Air Pollutants ◽  
Linear Equations ◽  
Measurement Data ◽  
Automatic Monitoring ◽  
Air Pollutant ◽  
Long Term Measurement

Abstract The purpose of the paper was to analyse the trends observed at air monitoring stations in the Malopolska Province - one of the most polluted regions in Poland. The study was carried out on the basis of long-term measurement data registered at five selected stations of automatic monitoring of air quality in the Malopolska Province. Trends evaluation was made on the basis of mean annual concentrations, taken from the database of the Chief Inspectorate for Environmental Protection in Poland. Separately for each basic air pollutant, such as SO2, NO2, NOx, CO, PM10 and O3, trend lines and their linear equations were determined to illustrate the direction of changes in concentrations. The obtained equations of the trend lines indicate the threat to the environment in the Malopolska Province. Based on the results obtained it can be concluded that for recent years there has been observed the concentration decrease of main air pollutants, except of tropospheric ozone.

Squall Detection and Analysis From Historical Satellite Data

2019 ◽  
Author(s):  
L. Renac ◽  
D. P. Hurdle ◽  
F. J. M. Enet ◽  
J. De Vroom
Keyword(s):  
Satellite Data ◽  
Measurement Data ◽  
Extreme Value Analysis ◽  
Intermediate Water ◽  
Design Data ◽  
Value Analysis ◽  
Design Values ◽  
The Impact ◽  
Long Term Measurement

Abstract Thunderstorms and squalls (fronts of contiguous thunderstorms) are associated with short but intense local winds that have a great impact on operability or design conditions for moored ship operations in the coastal zone. The brevity and local scale of such events makes them difficult to capture using standard measurement data and usually requires dedicated long-term measurement campaigns. Because the standard measurements available are usually based on 10-minute averages taken once an hour, such data is often not available. In the absence of conventional measured data, the use of satellite data can provide useful design data if analyzed and applied with caution. We present two case studies (West Africa and Brazil) where squalls have been identified in satellite data and used for extreme value analysis (EVA) to support the design of intermediate water depth mooring systems. The detection of squalls is confirmed with satellite imagery and the handling of this data for the EVA is presented in detail with assumptions made and the sensitivity of the results to these assumptions. The impact on design values is also discussed for both geographic locations.

scholarly journals Assessment of Causes and Effects of Groundwater Level Change in an Urban Area (Warsaw, Poland)

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3107
Author(s):  
Ewa Krogulec ◽  
Jerzy J. Małecki ◽  
Dorota Porowska ◽  
Anna Wojdalska
Keyword(s):  
Urban Area ◽  
Water Table ◽  
Groundwater Level ◽  
Anthropogenic Factors ◽  
Groundwater Levels ◽  
Quaternary Aquifers ◽  
Groundwater Quantity ◽  
The Impact ◽  
Long Term Measurement

Monitoring the data of groundwater level in long-term measurement series has allowed for assessment of the impact of natural and anthropogenic factors on groundwater recharge. It allows for assessing the actual groundwater quantity, which constitutes the basis for balanced and sustainable groundwater planning and management in an urban area. Groundwater levels in three aquifers were studied: the shallow and deeper Quaternary aquifers and the Oligocene aquifer in Warsaw (Poland). Statistical analysis was performed on a 27-year (1993–2019) cycle of daily measurements of groundwater levels. The studies focused on determining the range and causes of groundwater level changes in urban-area aquifers. The groundwater table position in the Quaternary aquifer pointed to variable long-term recharge and allowed for the identification of homogenous intervals with identification of water table fluctuation trends. A decrease in the water table was observed within the Quaternary aquifers. The Oligocene aquifer displayed an opposite trend.

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