• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.12 no.1
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• pp.37-43
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• 2006

PURPOSE: Previous studies have documented the lack of ultrasound's non-thermal effects on nerve conduction using frequencies of 1 MHz and 870 kHz. The purpose of this study was to determine the biophysical effects of continuous ultrasound on median local forearm temperature and motor nerve conduction velocities using frequencies of 3.0 MHz. SUBJECTS: Twelve healthy subjects (6 males, 6 females, age $22.30{\pm}2.41$ yrs, weight $61.33{\pm}10.16$ kg, height $167.58{\pm}8.04$ cm) without a history of neurological or musculoskeletal injury to their dominant arm volunteered for this study. METHODS AND MATERIALS: Each subject received a total of five treatments, one each at .0, 0.5, 1.0, 1.5, 2.0 W/$cm^2$ of 3 MHz continuous ultrasound on the anterior surface of the middle area of dominant forearm for 10 minutes. Dependent measures for forearm local temperature and median motor nerve conduction velocity (MNCV) were taken pretreatment and immediately post-treatment. One-way ANOVA were used for each dependent measure. RESULTS: The posttreatment forearm local temperature were differed significantly (p<0.001) between intensities of ultrasound. The posttreatment forearm local temperature of the ultrasound treated with 1.0 w/$cm^2$, 1.5 w/$cm^2$ and 2.0 w/$cm^2$ were significantly higher than 0.5 w/$cm^2$ and 0.0 w/$cm^2$ of ultrasound (p<0.05). The posttreatment median MNCV were differed significantly from the respective pretreatment velocities (p<0.001). The MNCV of the ultrasound treated with 0.0 w/$cm^2$ and 0.5 w/$cm^2$ were significantly (p<0.05) slower than that observed pretreatment, while the three ultrasound intensities produced significantly increased posttreatment MNCV: 1.0 w/$cm^2$ and 1.5 w/$cm^2$ and 2.0 W/$cm^2$. The posttreatment MNCV at 2.0 w/$cm^2$ and 1.5 w/$cm^2$ was significantly faster than that at 0 w/$cm^2$, 0.5 w/$cm^2$ and 1.0 w/$cm^2$ (p<0.05), the MNCV at 1.0 w/$cm^2$ was significantly faster than that associated with 0 w/$cm^2$ and 0.5 w/$cm^2$ of ultrasound (p<0.05). CONCLUSIONS: The decreased median motor forearm local temperature and MNCV of the ultrasound treated with 0.0 w/$cm^2$ and 0.5 w/$cm^2$ were attributed to the cooling effect by ultrasound transmission gel. Local forearm temperature and nerve conduction velocity were directly related to the intensity of ultrasound. Alterations in MNCV from ultrasound on healthy nerves appeared to be related to temperature changes induced by thermal effects of ultrasound.

• Corrosion Science and Technology
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• v.10 no.1
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• pp.37-42
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• 2011

Aluminum was electrochemically etched in acid solution and the surface area was magnified by the formation of etch pits. Etched aluminum was covered with a compact and dense dielectric oxide film by anodization and applied to the aluminum electrolytic capacitor electrode. Capacitance of aluminum electrolytic capacitor is closely related with surface area, which depends on size and number of etch pits. Size of etch pits need to be controlled because inside of the pits can be buried by the formation of dielectric oxide film. In this work, the effect of ultrasound pretreatment on the aluminum etch pit formation and capacitance were investigated. Additionally, the relationship between the second etching effect on pit size and capacitance was studied.

• Environmental Engineering Research
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• v.25 no.4
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• pp.470-478
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• 2020

Spent coffee grounds (SCG), the residue after brewing coffee beverage, is a promising biodiesel feedstock due to its high oil contents (15-20%). However, SCG should be pretreated to reduce the high free fatty acid content, which hampers transesterification reaction. To overcome this, we explored a direct transesterification reaction of SCG using ultrasound irradiation and identified the optimal sonication parameters. A high fatty acid methyl ester (FAME) content, up to 97.2%, could be achieved with ultrasound amplitude of 99.2 ㎛, irradiation time of 10 min, and methanol to oil ratio of 7:1 in the presence of potassium hydroxide concentration of 1.25 wt.%. In addition, we demonstrated that ultrasound irradiation is an efficient method to produce biodiesel from untreated SCG in a short time with less energy than the conventional mechanical stirring method. The physical and chemical properties of the SCG biodiesel met the requirements for an alternative fuel to the current commercial biodiesel.

• Food Science and Preservation
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• v.12 no.2
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• pp.130-134
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• 2005

This study was conducted to investigate the effects of pretreatment and extraction methods on the water extraction yields of sugar, protein and phenolic compounds, and the antioxidative activity of extract from Ganoderma lucidum. The herb was ground, sifted, and treated for 10 min with microwave (2,450 MHz) and ultrasound (20 kHz), and then extracted by boiling underatmospheric pressure and pressured boiling. Particle size $(0.8\~2.4\;mm)$, extraction time (2 hr) and solvent/solid ratio (20:1) were selected as optimal conditions for extraction.. Microwave and ultrasound treatment increased the extraction yields of total sugar, protein and phenolic compounds and the radical scavenging activity of extract. In comparison with microwave treatment and ultrasound treatment, microwave treatment was more effective than that of ultrasound treatment. The yields of all three compounds and the radical scavenging activity of extract were higher in pressured boiling extraction than in boiling underatmospheric pressure. The results showed that microwave radiation and sonication prior to extraction, and pressured extraction could be utilized for improving the extraction efficiency of G. lucidum.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1244-1252
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• 2013

Sugar beet pulp is an abundant industrial waste material that holds a great potential for bioethanol production owing to its high content of cellulose, hemicelluloses, and pectin. Its structural and chemical robustness limits the yield of fermentable sugars obtained by hydrolyzation and represents the main bottleneck for bioethanol production. Physical (ultrasound and thermal) pretreatment methods were tested and combined with enzymatic hydrolysis by cellulase and pectinase to evaluate the most efficient strategy. The optimized hydrolysis process was combined with a fermentation step using a Saccharomyces cerevisiae strain for ethanol production in a single-tank bioreactor. Optimal sugar beet pulp conversion was achieved at a concentration of 60 g/l (39% of dry weight) and a bioreactor stirrer speed of 960 rpm. The maximum ethanol yield was 0.1 g ethanol/g of dry weight (0.25 g ethanol/g total sugar content), the efficiency of ethanol production was 49%, and the productivity of the bioprocess was 0.29 $g/l{\cdot}h$, respectively.

• Food Science and Preservation
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• v.12 no.2
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• pp.146-150
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• 2005

A comparative study of pretreatment and extraction methods was conducted to investigate their effects on nutritional and bioactive components during hot-water extraction of Acanthopanax senticosus. The herb samples, ground and sifted $(8\~20\;mesh)$ were pretreated with ultrasound (20 kHz), microwave (2,450 MHz) or roasting $(180^{\circ}C)$ for 10 min, and then extracted by a boiling $(180^{\circ}C)$ under atmospheric pressure or a pressured boiling $(121^{\circ}C)$ for 2 hr. In general, the pretreatments improved the extraction efficiency and the DPPH radical scavenging activity of extract. Particularly, the extraction yields of soluble solids, total sugar and phenolic compounds were increased in microwaving methods, and the protein yield and the radical scavenging activity were higher in roosting pretreatment. Yields of soluble solids, total sugar, protein and phenolic compouds in pressured extraction were higher than those in nonpressured extraction. These results suggested that pretreatment including microwave radiation, sonication and roasting and pressured extraction can be utilized for improving the extraction efficiency of A. senticosus.

• Korean Journal of Animal Reproduction
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• v.21 no.2
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• pp.147-156
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• 1997

Ultrasound-guided follicular aspiration was performed in Holstein heifers once weekly with or without pretreatment of single or multiple decreasing doses using a total of 400 mg FSH. Oocytes were aspirated with a 6.5 MHz convex-array ultrasound trasducer designed for intravaginal use. All the visible follicles larger than 4 mm in diameter were punctured with a 17 gauge, 55 cm needle at each aspiration session and the follicular fluids containing oocytes were obtained by vacuum suction. The results obtained were as follows: As a preliminary experiment, the recovery rates of folicular oocytes by ultrasound-guided aspiration from the isolated ovaries of Korean native cows were compared between suction methods using manual syringe or vacuum pump. The recovery rate of oocytes using vacuum pump (80.7%) was significantly (P<0.05) higher than that using manual syringe (47.1%). The follicles were counted by their size in diameter with ultrasound image, and recovery rates and grades of follicular oocytes collected by ultrasound-guided aspiration were investigated in Holstein heifers pretreated with or without FSH. A group of heifiers were injected with multiple decreasing doses (twice a day for 3 days) of a total of 400 mg FSH. The other 2 groups were injected with a single dose of 400 mg FSH mixed with 25% PVP. Ultrasound observation of follicle population and/or ultrasound-guided transvaginal oocyte aspiration were performed 12 hrs following the last FSH injection in the multiple dose group, and 48 or 60 hrs after FSH injection in the single dose groups. Most of the visible follicles had small size of less than 3 mm in diameter in unstimulated heifers (71.0%), but medium size in all the heifers treated with FSH. (70.5 to 92.8%). The number of OPU follicles per session (4.6$\pm$1.9) were much less, compared to the vilsible follicle counts (9.7$\pm$2.2), in the nustimulated heifers due to the small dominant follicles. Among 4 goups of heifers the most visible as well as OPU follicles were observed in the heifers at 60 hrs following treatment of a single dose of 400 mg FSH (21.2$\pm$2.3 and 21.0$\pm$2.0), and the differences in both the follicle counts between the groups was found significant (P<0.05) The rates of oocyte recovery from the follicles by ultrasound-guilded aspiration were varied 46.3 to 75.0% in the heifers unstimulated and treated with a single dose of 400 mg FSH, but the group difference was not significant. The number of recovered oocytes per session a, pp.ared to be highest at aspiration at 60 hrs following single FSH (10.6$\pm$2.2) than at aspiration at 48 hrs after single FSH (7.8$\pm$2.7) or in the unstimulated heifers (3.4$\pm$3.0). The proportion of grade I and II oocytes to all oocytes collected was varied 31.8 to 64.0% between the groups. However, there was found no significant difference in both the number of oocytes recovered per session and the percentage and the percentage of grade I and II oocytes. From the above results it was concluded that the more oocytes of superior quality might be recovered economically by ultrasound-guided aspiration at 60 hrs following the pretreatment of a single dose of 400 mg FSH and by suction using a vacuum pump system of about negative pressure of 75 to 85 mmHg.

• Journal of Environmental Science International
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• v.16 no.2
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• pp.211-218
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• 2007

The objectives of this study have been carried out to investigate the solubilization of municipal sewage sludge by single and dual frequency ultrasonic pretreatment, and the methane production characteristics of pretreated sewage sludge by specific methanogenic activity test for sewage sludge reduction. The waste activated sludge was collected from thickened tank of Suyoung sewage treatment plant in Busan city, and its concentration was adjusted to 1.0% total solids. Ultrasonic frequency was varied 15, 20, 15+20 kHz, and acoustic density was used a maximum 176W/L. The dual frequency ultrasonic pretreatment was found to be more effective than single frequency ultrasonic in the solubilization rate and methane production. The $SCOD_{Cr}/TCOD_{Cr}$, rate were 15.2%, 13.9%, 17.0% with single frequency of 15 kH2, 20 kHz, dual frequency of 15+20 kHz, respectively. The application of dual frequency ultrasound for sewage sludge pretreatment can be interest for sewage treatment plants having problems in sludge treatment and disposal.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.6
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• pp.893-906
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• 2011

The effect of ultrasound pretreatment on sludge degragability was investigated at different condotions: ultrasonic frequency(28, 40, 50kHz), intensity(10, 25, 50W), sonication time(10, 20, 30, 60min). Total suspended solid(TSS) and soluble chemical oxygen demand(SCOD) concentration were measured for the evaluation of pretreatment efficiency. The pretreated sludge was used as the feedstock for anaerobic digestion process. Biogas production and volatile suspended solid(VSS) removal were determined for evaluating the process performance. 1. TSS concentration of the sludge decreased at a constant rate as sonication operation was applied. The degradation rate of TSS increased when ultrasound frequency was decreased from 50kHz to 28kHz and intensity was increased from 10W to 50W. Efficiency of TSS degradation per input energy increased as ultrasonic frequency and intensity were decreased. At the frequency of 28 and 40kHz, SCOD concentration rapidly increased during the initial 30min of sonication time, and then it gradually increased. At 50kHz, SCOD concentration constantly increased for 60min of the sonication time. The SCOD production rate increased with increasing intensity under all ultrasound frequencies. 2. The optimum condition of ultrasound treatment was 28kHz, 50W and 60min for maximizing the biogas production, methane fraction, VSS removal. The highest values in biogas production, methane fraction in biogas, VSS removal were 370ml, 70%, 2.45g, respectively. Methane production rate per input energy increased at ultrasonic frequency and intensity decreased. 3. When raw sludge was pretreated at the condition of ultrasonic frequency of 28 and 40kHz in series, sequential-frequency sonication, intensity of 50W and 60min, biogas production, methane fraction, VSS removal were about the same that of 28kHz single-frequency sonication. When sequential-frequency sonication of 28 and 50kHz was applied in series, biogas production, methane fraction, VSS removal were 356 ~ 423ml, 69 ~ 71%, 2.41 ~ 2.78g, respectively. The pretreatment efficiency of 28-50kHz sequential-frequency sonication which sonication time of 28kHz and 50kHz was 40min and 20min was higher than that of 28kHz single-frequency sonication.

• International journal of advanced smart convergence
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• v.5 no.2
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• pp.18-23
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• 2016

Cell walls of microalgae consist of a polysaccharide and glycoprotein matrix providing the cells with a formidable defense against its environment. Anaerobic digestion (AD) of microalgae is primarily inhibited by the chemical composition of their cell walls containing biopolymers able to resist bacterial degradation. Adoption of pre-treatments such as thermal, thermal hydrolysis, ultrasound and enzymatic hydrolysis have the potential to remove these inhibitory compounds and enhance biogas yields by degrading the cell wall, and releasing the intracellular algogenic organic matter (AOM). This paper preproposal stage investigated the effect of different pre-treatments on microalgae cell wall, and their impact on the quantity of soluble biomass released in the media and thus on the digestion process yields. This Paper present optimum approach to degradation of the cell wall by ultra-sonication with practical design specification parameter for ultrasound based pretreatment system. As a result of this paper presents, a microalgae system in a wastewater treatment flowsheet for residual nutrient uptake can be justified by processing the waste biomass for energy recovery. As a conclusion on this result, Low energy harvesting technologies and pre-treatment of the algal biomass are required to improve the overall energy balance of this integrated system.