• Food Science and Biotechnology
• /
• v.17 no.5
• /
• pp.895-898
• /
• 2008

The mobility of water in set yogurt during fermentation was studied using nuclear magnetic resonance (NMR) relaxometry. The spin-spin relaxation was analyzed using a 2-fraction model, resulting in 2 spin-spin relaxation time constants $T_{21}$ and $T_{22}$. Both $T_{21}$ and $T_{22}$ exhibited rapid changes between 2 and 4 hr of fermentation, coinciding with the drop in pH and the rise in lactic acid bacteria count. The spin-lattice relaxation time $T_1$ increased over the fermentation period. Both $T_1$ and $T_2$ showed an increase in the mobility of water upon gel formation during fermentation. Water redistribution within the gel matrix due to casein aggregation and structure forming may be responsible for the changes in mobility.

• International Journal of Precision Engineering and Manufacturing
• /
• v.9 no.3
• /
• pp.13-17
• /
• 2008

This paper deals with the directional mobility of droplets on structured surfaces. Structured surfaces were micro-patterned with rectangular lines and spaces of varying pitch and height in the sub-millimeter range. The material used was polydimethylsiloxane, which is hydrophobic and wettable by oil. First, we studied the effect of the structural design on the sliding angle of pure water or oil through experiments. For pure water droplets, we found that a wider pitch enhanced the directionality. On the other hand, oil droplets spread along the groove because of their low surface tension and strong capillary force. The directionality of the sliding angle of oil droplets was larger than that of pure water, especially when the groove was narrower and deeper. Second, we poured a large amount of liquid on the structure and evaluated the removal rate on the tilted surface. We found that a parallel structure enhanced the liquid mobility for both pure water and oil.

• Journal of Korean Society on Water Environment
• /
• v.27 no.1
• /
• pp.115-119
• /
• 2011

The mobility of groundwater in the soil environment has an important role in the soil environment and absorption of plant. Therefore, studies on the mobility of groundwater considering the physical and chemical properties of soil is very important. In this study, movement of water due to change in soil particle size were observed by capillary rise. The height of the capillaries was measured according to capillary diameter, temperature and solution concentration. The inner diameter of each capillary itself is 0.012, 0.016, 0.024, 0.027 cm, and experiments were performed at $22^{\circ}C$. As a result, the height of the capillaries decreased with increasing capillary diameter, and the solution temperature but increased with increasing concentration. Changes in the height of the capillaries are interpreted to related with surface tension by the Young-Laplace equation. Also on the mobility of groundwater, the increase of water and soil temperatures can be significant factors caused by ion strength and global warming as well as pores in the soil particles. The results of this study is considered to provide the basic data on the behavior of groundwater in the soil environment.

• Korean Journal of Food Science and Technology
• /
• v.25 no.6
• /
• pp.742-746
• /
• 1993

Retrogradation of legume starches and their gel properties were studied. From DSC results, kidney bean starch retrograded faster than other starches whereas cow pea and mung bean starches retrograded slowly. Retrogradation rate of 1% starch solutions during storage showed similar patterns to the DSC results. During storage, the sags of cow pea and mung bean gels(starch conc., 8%) were slowly increased, but that of kidney bean was rapidly increased. The water mobility of cow pea and mung bean gels, which was measured by NMR, remained unchanged for one day, afterwards decreased slowly, whereas that of red bean and kidney bean gels decreased rapidly through the storage time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.300-302
• /
• 2022

In this paper, We propose a mobility model-based resource collision avoidance technique that can share radio resources without resource collision between UAV in a FANET environment. The proposed technique tries to reduce the occurrence of resource collisions by estimating UAV mobility based on information obtained from GPS devices installed in UAV. Through simulations, The performance was compared with the contention-based protocol, and it was confirmed that the proposed algorithm can reduce resource collisions.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.8
• /
• pp.1154-1158
• /
• 2006

Anomalously high ionic mobilities of H+ and $OH^-$ are owing to the transfer of $H^+$ by the Grotthus chain mechanism. Molecular dynamics simulations for the system of 215 water including $OH^-$ ion at 298.15 K using the OSS2 model [J. Chem. Phys. 109, 5547 (1998)] as a dissociable water model with the use of Ewald summation were carried out in order to study the dynamics of $OH^-$ in water. The calculated ionic mobility of $OH^-$ is in good agreement with the experimental result and the Grotthus chain mechanism is fully understood.

• Journal of Korean Society of Water and Wastewater
• /
• v.32 no.3
• /
• pp.243-251
• /
• 2018

In this study, we compared the MZVI (Microscale Zero-Valent Iron) and NZVI (Nanoscale Zero-Valent Iron) for reactivity and mobility in a column to reduce nitrate, which is a major pollutant in Korea, and investigated the effect of operational parameters on the NZVI filled column. For the comparison of MZVI and NZVI, samples were collected for 990 minutes using fractionator in the similar operation conditions (MZVI 10g, NZVI 2g). The nitrate reduction efficiency of NZVI was about 5 times higher than that of MZVI, which was about 7.45% and 38.75% when using MZVI and NZVI, respectively. In the mobility experiment, the MZVI descended due to gravity while NZVI moved up with water flow due to its small size. Furthermore, the optimum condition of NZVI filled column was determined by changing the flow rate and pH. The amount of Fe ions was increased as the pH of the nitrate solution was lowered, and the nitrate removal rate was similar due to the higher yield of hydroxyl groups. The removal rate of nitrate nitrogen was stable while flow rate was increased from 0.5 mL/min to 2.0 mL/min (empty bed contact time: 2.26 min to 0.57 min). NZVI has a high reduction rate of nitrate, but it also has a high mobility, so both of reactivity and mobility need to be considered when NZVI is applied for drinking water treatment.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.18 no.2
• /
• pp.125-130
• /
• 2015

Vehicles and UGV(Unmanned Ground Vehicle) need a variety of road informations, such as road profile, soil type and soil water contents, to run a cross country course. Especially, soil water contents are very important factor to judge the vehicle mobility, because it can change soil strength. This paper describes the real-time measuring method of soil water contents by using the soil thermal conductivity.

• Journal of Korean Society on Water Environment
• /
• v.20 no.6
• /
• pp.676-684
• /
• 2004

Many researchers have been carrying on study to figure out the exact collision efficiency between bubble and floc. Collision efficiency can has generally been quantified by using trajectory analysis which uses the hydrodynamic, the electrostatic and van der waals forces. Two types of method are considered to induce the hydrodynamic force in the trajectory analysis. One is to use stream function and the other is to use mobility function. There was some difference between stream and mobility function depending upon modelling factors and conditions in trajectory analysis.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1995.04a
• /
• pp.94-99
• /
• 1995

Naphthalene sulfonated condensatd(NSF) has been widely using for the superplasticizing of ement and concrete. But NSF has a very large mobility loss with elapsed tiom. To retain mobility of NSF during a certain time, maleic anhydride and acrylic acid copolymer(MA) was polymerized and mixed with NSF in order to perpare admixture holding mobility-retention property of cement. By applying this admixture for ement paste, we examined the fluidity and mobility retention property as a function to elapsed time and measured the compressive strength of mortar with curing time. As a result, NSF containing 20wt% of MA showed very excellent fluidity and mobility-retention property. These properties were affected by the added amount of admixture and the ratio of water to cement.