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

• Journal of radiological science and technology
• /
• v.43 no.5
• /
• pp.359-365
• /
• 2020

This study aimed to investigate the causes of bacterial growth to prevent infection caused by ultrasound gel and gel containers in contact with patients during ultrasonography. To investigate bacterial contamination during manufacturing or storage, we cultured ultrasound gels originally supplied from three manufacturers. To analyze bacterial growth according to the lapse of time and frequency of use of the ultrasound gel container, the gel and container were cultured at regular intervals every week for 4 weeks. In addition, to determine the source of infection, the examiner's hand was inspected with hand plate and the degree of bacterial contamination was measured before the test. As a result of the study, bacteria were not detected in the gel provided at the initial supply, and in the gel and gel container used repeatedly for 4 weeks, the same bacteria residing on the skin were identified in the examiner's hand, such as Staphylococcus epidermidis, Micrococcus luteus, Leuconostoc mesenteroid spp cremoris, Kocuria rhizophila, and etc. Separated strains were classified as those of the low- or non-pathogenicity; however, most of these strains may render fatal consequences to patients of lower level of immunity due to acquired tolerance to antibiotics. At week 1, when the number of tests was the highest, 44 colonies were identified, and at week 4, when the number of tests was the lowest, 4 colonies were identified. As r=0.994, it was found that the number of colonies increased as the number of tests increased. In conclusion, it was confirmed that the cause of the infection was not the ultrasound gel, but the examiner's hand. The ultrasound gel or gel container may be contaminated by skin flora of examiner's hands, which can cause opportunistic infection in patients with low immunity. The ultrasound gel or gel container may be contaminated by skin flora of examiner's hands, which can cause opportunistic infection in patients with low immunity. Therefore, it was confirmed that thorough hand disinfection was necessary to block healthcare-associated infections.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.30 no.6
• /
• pp.564-568
• /
• 2010

When ultrasound propagates to a crack, transmitted and reflected waves are generated. These waves have useful information for the detection of the crack lying in a structure. When a crack is under residual stress, crack surfaces will contact each other and a closed crack is formed. For closed cracks, the fundamental component of the reflected and transmitted waves will be weak, and as such it is not easy to detect them. In this case, higher harmonic components will be useful. In this paper, nonlinear characteristic of a closed crack is modeled by a continuum material having a tensile-compressive unsymmetry, and the amplitude of the second harmonic wave was obtained by spectrum analysis. Variation of the second harmonic component depending on the nonlinearity of the inclusion was investigated. Two-dimensional plane strain model is considered, and finite element software ABAQUS/Explicit is used.

• Journal of Industrial Technology
• /
• v.25 no.A
• /
• pp.87-93
• /
• 2005

Three-dimensional ultrasonic probes being applied to the medical imaging can be grouped into three depending on the scanning methods, which are a mechanical type system, a free-hand system, and 2D phased arrays system. A mechanical type scanner uses a mechanically driven transducer to acquire series of 2D plane images. By integrating these images, a 3-D medical image can be constructed. A motor driving mechanism is a conventional choice for mechanically driving a transducer assembly which picks the raw ultrasonic images up. In this paper we attempt to design a 3D ultrasonic probe which has a operating mechanism of s tilting 3-D scanning. The motion of a transducer assembly of the ultrasonic probe is analytically modelled. We propose a selection procedure for the diameter of a wire rope driving the transducer assembly and the size of torsional spring which gives an initial tension to wire ropes.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.13 no.5
• /
• pp.419-424
• /
• 2020

Poroelasticity theory has been widely used for detecting cancellous bone deterioration because of the safe use for humans. The tortuosity itself is an important indicator for ultrasound detection for bone diseases. The transport properties of cancellous bone are also important in bone mechanotransduction. In this paper, two important factors, the wave velocity and attenuation are examined for permeability (or tortuosity). The theoretical calculation for the relationship between the wave velocity (and attenuation) and permeability (or tortuosity) for cancellous bone is shown in this study. It is found that the wave along the solid phase (trabecular struts) is influenced not by tortuosity, but the wave along the fluid wave (bone fluid phase) is affected by tortuosity significantly. However, the attenuation is different that the attenuation of a fast wave has less influence than that of a slow wave because the slow wave is observed by the relative motion between the solid and fluid phases.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.32 no.3
• /
• pp.307-313
• /
• 2012

• Journal of Animal Science and Technology
• /
• v.52 no.1
• /
• pp.1-8
• /
• 2010

This study is conducted to use the real-time ultrasound measurement data of Hanwoo as basic data being available to improvement. We used the ultrasound measurement data of 1,125 heads of performance tested cattle and the carcass data after castrating at about 12 months of age, fattened to 30 months, and then sold. For 921 heads of progeny tested cattle, we used test data and slaughter data. Heritabilities of ultrasound data for longissimus muscle area and backfat thickness measured at 12 months of age were estimated as 0.57 and- 0.41, respectively, and at 24 months of age, it was 0.57 and- 0.60, respectively, with high heritability. However, in estimation value of heritability containing ultrasound measurement for percent intramuscular fat, it showed low and medium heritability as 0.14 at 12 months of age and 0.22 at 24 months of age for each. The longissimus muscle area, backfat thickness, and percent intramuscular fat of ultrasound measure traits and longissimus muscle area, backfat thickness, marbling score of carcass traits genetic correlation of at 12 months of age were estimated as 0.616, 0.544, 0.501, respectively and at 24 months of age, it showed high genetic correlation as 0.894, 0.937, 0.263, respectively. As a result of ranking correlation between selection index by using weight, carcass traits at 12 months of age and selection index based on ultrasound measurement data which has high genetic correlation, in data of ultrasound measurement at 12 months of age, it showed high ranking correlation as that selection index of young bull was 0.140 and that of proven bull was 0.843.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2004.12a
• /
• pp.97-98
• /
• 2004

• Journal of Industrial Technology
• /
• v.8
• /
• pp.65-70
• /
• 1988

The intensity of ultrasound in liquid is calculated by improved analytic method. Helmholtz equation or Rayleigh's proposition does not offer the analytic solution. Considering a bounded medium, the use of the image source method in electromagnetic thoery gives a new way of calculating the total ultrasonic intensity in liquid. Some methods of measuring the intensities are also mentioned.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.22 no.2
• /
• pp.140-148
• /
• 2002

Anisotropic elastic constants of Zr-2.5Nb pressure tube materials were determined by a high temperature resonant ultrasound spectroscopy (RUS). The resonant frequencies were measured using alumina wave-guides and wide band ultrasonic transducers in a small furnace. The rectangular parallelepiped specimens were fabricated along with the axial, radial and circumferential direction of the pressure tube. A nine elastic stiffness tensor for orthotropic symmetry was determined in the range of room temperature ${\sim}500^{\circ}C$. As the temperature increases, the elastic constant tensor, cij gradually decreases. Higher elastic constants along the transverse direction compared to those along the axial or radial direction are similar to the case of Young's modulus or shear modulus. A crossing of shear elastic constants along axial direction and radial direction was observed near $150^{\circ}C$. This fact corresponds to the crossing of c44 and c66 of single crystal zirconium.