scholarly journals Water as a tuneable solvent: a perspective

2020 ◽  
Vol 49 (9) ◽  
pp. 2557-2569 ◽  
Author(s):  
Eric Breynaert ◽  
Maarten Houlleberghs ◽  
Sambhu Radhakrishnan ◽  
Gerhard Grübel ◽  
Francis Taulelle ◽  
...  

Water is the most sustainable solvent, but its polarity limits the solubility of non-polar solutes. Confining water in hydrophobic nanopores could be a way to modulate water solvent properties and enable using water as tuneable solvent (WaTuSo).

2017 ◽  
Vol 19 (7) ◽  
pp. 5254-5261 ◽  
Author(s):  
L. A. Ferreira ◽  
V. N. Uversky ◽  
B. Y. Zaslavsky

Distances between the signatures of salt effects on water solvent features depend on static polarizability of the anion and water structural entropy.


2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Fina Supegina

Hydroponics is one of planting method that use water as a medium of plants growth, in this technique, mineral solution added into the water solvent, allowing the nutrient uptake process by the plants.  Farming by hydroponic method must pay attention to the following parameters namely, temperature, humidity, the level of water needs and nutrients and also the level of sunlight need for photosynthesis process.  This research used hydroponic technique in hydroponic growth room, and  there is a LED growth light as an alternate of sunlight, due to this room is closed without sunlight.  There are outputs displayed in monitoring system namely, temperature sensor, humidity sensor, ultrasound sensor to detect height of the plant and water level sensor to measured height of the water as a medium of the plant.  Results of measured sensor in hydroponic growth room explained as the following:  fan cooler worked when temperature , and humidity  .  Water pump worked when water level is less than 50% accordance set point.  Control on LED Growth Light and LED Bulb when LDR sensor reached set point > 500 in bright condition, and < 500 in dark condition respectively. The average of Time update/received data in thing speak web is 2.4 second. Keywords: Smart Control, Hydroponic, IoT, Monitoring


2020 ◽  
Vol 2 (1) ◽  
pp. 11-20
Author(s):  
Meta Kartika Untari ◽  
Ganet Elo Pramukantoro

Hypercholesterolemia is a state of increased levels of LDL (Low Density Lipoprotein) and total cholesterol in the plasma. Stevia leaves have benefits to overcome hypercholesterolemia. The aimed of this study was to obtain ethanol extracts of Stevia rebaudiana Bertoni leaves which have activity to reduce total cholesterol levels in patients with hypercholesterolemia with effective doses. The method that will be carried out to achieve this goal was to make extracts by maceration of Stevia rebaudiana Bertoni leaf powder using a water solvent for 5 days. Testing antihypercholesterolemia activity by giving treatment to 20 male white rats. Rats were divided into 5 treatment groups. Group I was negative control, II was simvastatin control, III extract was 30 mg / 200 g BW, IV extract was 60 mg / 200 g BW, V extract was 120 mg / 200 g BW. The mice were induced by propylthiouracil 12.5 mg / day and high-fat feed for 21 days, after which the rats were given the test for 14 days. Cholesterol levels were measured on days 0, 21st and 28th. The method of determining cholesterol levels uses the Easy Touch tool. On the 35th day, a total cholesterol level was examined and data analysis was performed. The results showed that the ethanol extract of stevia leaves had antihypercholesterolemia activity, extract dose of 30 mg / 200 g BW had antihypercholesterolemia activity which was equivalent to simvastatin.


2012 ◽  
Vol 116 ◽  
pp. 190-194 ◽  
Author(s):  
Yu Yang ◽  
Changwei Hu ◽  
Mahdi M. Abu-Omar
Keyword(s):  

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3777
Author(s):  
Yuemei Ye ◽  
Jingwen Sun ◽  
Liting Wang ◽  
Junwang Zhu ◽  
Wei Cui ◽  
...  

As an abundant marine xanthophyll, fucoxanthin (FX) exhibits a broad range of biological activities. The preparation of high-purity FX is in great demand, however, most of the available methods require organic solvents which cannot meet the green chemistry standard. In the present study, a simple and efficient purification approach for the purification of FX from the brown seaweed Sargassum horneri was carried out. The FX-rich ethanol extract was isolated by octadecylsilyl (ODS) column chromatography using ethanol–water solvent as a gradient eluent. The overwhelming majority of FX was successfully eluted by the ethanol–water mixture (9:1, v/v), with a recovery rate of 95.36%. A parametric study was performed to optimize the aqueous ethanol precipitation process by investigating the effects on the purity and recovery of FX. Under the optimal conditions, the purity of FX was 91.07%, and the recovery rate was 74.98%. Collectively, the eco-friendly method was cost-efficient for the purification of FX. The developed method provides a potential approach for the large-scale production of fucoxanthin from the brown seaweed Sargassum horneri.


2021 ◽  
Vol 11 (15) ◽  
pp. 7106
Author(s):  
Miaotian Sun ◽  
Zeynep Ülker ◽  
Zhixing Chen ◽  
Sivaraman Deeptanshu ◽  
Monika Johannsen ◽  
...  

The retention factor is the key quantity for the thermodynamic analysis of the retention mechanism in chromatographic experiments. In this work, we measure retention factors for moderately polar solutes on four silica-based porous matrices as stationary phases by supercritical fluid chromatography. Elution of the solutes is only possible with binary mixtures of supercritical carbon dioxide (sc-CO2) and modifier (methanol) due to the low polarity of pure sc-CO2. The addition of modifiers makes the retention mechanism more complex and masks interactions between solute and stationary phase. In this work, we develop and validate several retention models that allow the obtaining of retention factors in modifier-free sc-CO2. Such models pave the way for quantifying adsorption interactions between polar solutes and non-swellable porous matrices in pure sc-CO2 based on retention data obtained in sc-CO2/modifier mixtures. The obtained information will thereby facilitate the understanding and design of impregnation processes, which are often performed in modifier-free conditions.


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