• Journal of Korean Society on Water Environment
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• v.35 no.2
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• pp.115-122
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• 2019

The objective of this study was to investigate the sonophysical and sonochemical effects induced by acoustic cavitation in heterogeneous systemin a 28 kHz double-bath reactor using calorimetry, the aluminiumfoil erosion test, and the luminol test. With no glass beads, calorimetric power in the inner vessel increased as much as the outer sonoreactor lost and total calorimetric power was maintained for various liquid height conditions (0.5 ~ 7 cm) in the vessel. Higher calorimetric energy was obtained at higher liquid height conditions. Similar results were obtained when glass beads were placed with various beads heights (0.5 ~ 2.0 cm) and relatively high calorimetric energy was obtained in spite of large attenuation in the glass beads layer. An aluminium foil placed between the bottom of the inner vessel and the glass beads layer was damaged, indicating significant sonophysical effects. Much less damage was detected when the foil was placed above the beads layer due to large attenuation of ultrasound. Sonochemical effects, visualized by sonochemiluminescence (SCL), also decreased significantly when the beads were placed in the vessel. It was established that the optimization of the liquid height above the solid-material layer could enhance the sonophysical and sonochemical effects in the double-bath sonoreactors.

• Journal of the Korean Society of Food Culture
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• v.22 no.6
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• pp.841-847
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• 2007

This study was conducted to investigate on bone density and nutrient intake of university students in Seoul area. Nutrient intake data were obtained by using the 24-hour recall method to evaluate the usual diet of the subjects. BQI(bone quality index) of the subjects was measured by an Quantitative Ultrasound (QUS). The results are summarized as follows: The average height, weight, BMI of the male and female student were 173.3 cm, 68.5 kg, 22.7; 161.4 cm, 54.2 kg, 20.8, respectively. The BQI and Z-score of the subjects were 99.50, -0.69 in male student group, and 82.6, -1.15 in female student group, respectively. Normal, osteopenia and osteoporosis percentage by bone status were 73.8%, 24.9%, 1.3% in male student group, and 39.8%, 57.6%, 2.6% in female student group, respectively. Energy intake of male and female group were 71.7%, 79.1% of EER(estimated energy requirement) respectively. Fiber, Ca, Vit $B_2$, niacin, folic acid, Vit C intake were less than RI(recommended intake) and protein, phosphorus intake were higher than RI in subjects. Nutrient intake were not significantly related with BQI in male and female groups generally.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.05a
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• pp.37-40
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• 2000

Acoustically enhanced soil flushing method is a newly developed in-situ remediation technique. However, there has not been an analytical method that can be used to evaluate the effectiveness of ultrasonic wave under different conditions. This study was undertaken to investigate the degree of enhancement in contaminant removal due to ultrasonic energy on the soil flushing method. The test conditions included different levels of ultrasonic power and hydraulic gradient. The test soils were Ottawa sand, a fine aggregate, and a natural soil, and the surrogate contaminant was a Crisco Vegetable Oil. The test results showed that sonication could increase contaminant removal significantly. Increasing sonication power increased pollutant removal. The faster the flow is, the smaller the degree of enhancement will be. The pollutants in dense soils are more difficult to be removed than in loose soils.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.655-658
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• 2002

The present paper investigated the effect of ultrasonic vibrations on the melting process of a phase-change material (PCM). Furthermore, the present study considered constant heat-flux boundary conditions unlike many of the previous researches, which had adopted constant wall-temperature conditions. Therefore in the study, modified dimensionless numbers such as Stefan and Rayleigh were adopted to represent heat transfer results. The experimental results revealed that ultrasonic vibrations accompanied the effects like agitation, acoustic streaming, cavitation, and oscillating fluid motion, accelerating the melting process as much as 2.5 times, compared with the result of natural melting (i. e., the case without ultrasonic vibration). Such effects are believed to be a prime mechanism in the overall melting process when ultrasonic vibrations were applied. Subsequently, energy could be saved by applying the ultrasonic vibrations to the natural melting In addition, various time-wise dimensionless numbers provided a conclusive evidence of the important role of the ultrasonic vibrations on the melting phenomena of the PCM.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.418-421
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• 2002

The immunity testing in this study was performed to examine the conducted immunity and radiated immunity in medical instrumentation. Experiments were performed to assess the conducted emission and radiated emission of medical instrumentation such as MRI, ultrasound system, and electro surgical unit etc. The emission testing revolves around conducted emissions (high-frequency currents) on power lines and signal cables. Emission testing also looks at the output of energy through the air (called radiated emissions) and analyzes the strength of those radio-frequency signals generated unintentionally by the electrical medical device that is under test. Finally, this study would provide significant data for furture research or electromagnetic interference and compatibility test in medical instrumentation.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.14 no.1
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• pp.61-65
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• 2008

Purpose : The purpose of the study was to determine Effects of application on manual therapy of knee pain cause of Sacroiliac joint dysfunction. Methods : The patient with knee pain was 59years female. Muscle Energy Techniques, high-velocity, low-amplitude and modality(Hot pack, ultrasound, TENS) using during one month. Results : The patient has improve pain, muscle strength and function.

• Elastomers and Composites
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• v.31 no.3
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• pp.175-182
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• 1996

Polymer latices, prepared from the emulsion polymerization of vinyl monomer compounds, are widely used for many industrial applications. Included among these are uses in paints, adhesives, flocculants, and heavy-duty plastics as well as their original use in synthetic rubber compounds. The emulsion polymerization process with chemical initiator has chemical disadvantage such as removal of initiator which was left after polymerization. In this study, polystyrene latex was prepared by using ultrasonic irradiation which generate the free radical, and then it was analyzed by GPC. Reaction temperature hardly have an effect on average molecular weight. Average molecular weight is increased by increasing amount of surfactant, i.e. SDS, but polydispersity is decreased. After 90 minutes of reaction time, increase and decrease of average molecular weight Is repeated. It is proposed that monodisperse polymer is obtained by controlling ultrasonic irradiation time and surfactant concentration.

• Medical Lasers
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• v.10 no.1
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• pp.15-21
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• 2021

As technology advances at a rapid rate, innovations in regenerative medicine will eventually include the use of energy-based therapeutics, such as low intensity-pulsed ultrasound stimulation (LIPUs), pulsed electromagnetic field stimulation (PMFs), and low-level laser/light therapy (LLLt) or photobiomodulation therapy (PBMt). Among these treatments, LLLt/PBMt attracted significant attention by the turn of the century, as evidenced by the numerous publications compared to LIPUs and PMFs, particularly for augmented bone regeneration (ABR). This is a testament of how the maturation of technology and scientific knowledge leads to latent compounded applications, even when the value of a technique is reliant on empirical data. This article reviews some of the notable investigations using LLLt/PBMt for bone regeneration published in the past decade, focusing on how this type of therapy has been utilized together with the existing regenerative medicine landscape.

• Advances in concrete construction
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• v.13 no.1
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• pp.25-34
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• 2022

The production of geopolymer is considered as a cleaner process due to much lower CO₂ emission than that from the production of Portland cement. This paper presents a study of the potential use of recycled steel fibre (RSF) coming from the recycling process of the old tires in geopolymer mortars. Ground expanded perlite (EP) is used as a source of alumino-silicate and sodium hydroxide (NaOH=5, 10, 15, and 20M) is used as alkaline medium for geopolymer synthesis. RSFs were added to the mortar mixtures in four different volume fractions (0, 0.5, 1.0, and 1.5% of the total volume of mortar). The unit weight, ultrasound pulse velocity, flexural and compressive strength of expanded perlite based geopolymer mortar (EPGM) mixtures were determined. The microstructures of selected EPGMs were examined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analyses. The optimum molarity of sodium hydroxide solution was found to be 15M for geopolymer synthesis by EP. The test results revealed that RSFs can be successfully used for fibre-reinforced geopolymer production.

• Food Science and Preservation
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• v.30 no.1
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• pp.122-131
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• 2023

Persimmon peels are mostly discared as a by-product of dried persimmon manufacturing, but effective use is required as it contains various functional constituents. This study covers the preparation of carotenoid-enriched oil by ultrasound treatment of persimmon peel in soybean oil solvent, and the investigation of its physicochemical characteristics. Using the Box-Behnken design and response surface methodology, the optimal extraction conditions (temperature, 62℃; time, 32 min; and persimmon peel to oil ratio, 1:3.1) were determined based on the carotenoid concentration of the extract. The physicochemical characteristics of the extract obtained under optimal conditions and the untreated soybean oil (control) were compared. The total carotenoid content of the extract increased. The carotenoid-enriched soybean oils had a lighter color than the controls, but with high redness and yellowness values. The effect of sonication and a component of the persimmon peel on the oxidation and heating stability of soybean oil was weak. The viscosity and activation energy of carotenoid-enriched soybean oil were slightly higher than those of the control. Thus, it was possible to prepare yellow-red carotenoid-enriched soybean oil by applying ultrasonic-soybean oil solvent extraction to persimmon peel. The oil is expected to be useful as an additive as well as a substitute for general edible oils.