• Food Science and Biotechnology
• /
• v.14 no.4
• /
• pp.470-473
• /
• 2005

Starch was isolated from turnip (Brassica rapa L.), and to elucidate the structure-function relationship its structural and physical properties were characterized. Morphological structure of the starch was analyzed by SEM (Scanning Electron Microscopy). Most of the starch granules were spherical in shape with diameter ranging from 0.5-10mm. Apart from larger granules ($<10\;{\mu}m$) which dominated the population size of turnip starch, significant amount of small ($0.5-2\;{\mu}m$) and mid-size granules (${\sim}\;{\mu}m$) were also detected. It was revealed that presumably, erosion damages occurred due to the attack of amylase-type enzymes on the surface of some granules. Branch chain-length distribution was analyzed by HPAEC (High-Performance Anion-Exchange Chromatography). The chain-length distribution of turnip starch revealed a peak at DP12 with obvious shoulder at DP18-21. The weight-average chain length ($CL_{avg}$) was 16.6, and a large proportion (11.8%) of very short chains (DP6-9) was also observed. The melting properties of starch were determined by DSC (Differential Scanning Calorimetry). The onset temperature ($T_o$) and the enthalpy change (${\Delta}H$) of starch gelatinization were $50.5^{\circ}C$ and 12.5 J/g, respectively. The ${\Delta}H$ of the retrograded turnip starch was 3.5 J/g, which indicates 28.2% of recrystallization. Larger proportion of short chains as well as smaller average chain-length can very well explain relatively lower degree of retrogradation in turnip starch.

• ETRI Journal
• /
• v.26 no.6
• /
• pp.520-534
• /
• 2004

As the density of memories increases, unwanted interference between cells and the coupling noise between bit-lines become significant, requiring parallel testing. Testing high-density memories for a high degree of fault coverage requires either a relatively large number of test vectors or a significant amount of additional test circuitry. This paper proposes a new tiling method and an efficient built-in self-test (BIST) algorithm for neighborhood pattern-sensitive faults (NPSFs) and new neighborhood bit-line sensitive faults (NBLSFs). Instead of the conventional five-cell and nine-cell physical neighborhood layouts to test memory cells, a four-cell layout is utilized. This four-cell layout needs smaller test vectors, provides easier hardware implementation, and is more appropriate for both NPSFs and NBLSFs detection. A CMOS column decoder and the parallel comparator proposed by P. Mazumder are modified to implement the test procedure. Consequently, these reduce the number of transistors used for a BIST circuit. Also, we present algorithm properties such as the capability to detect stuck-at faults, transition faults, conventional pattern-sensitive faults, and neighborhood bit-line sensitive faults.

• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.3395-3400
• /
• 2007

Heat transfer experiments at a vertical annulus passage were carried out in the SPHINX(Supercritical Pressure Heat Transfer Investigation for NeXt Generation) to investigate the heat transfer behaviors of supercritical $CO_2$. The collected test data are to be used for the reactor core design of the SCWR (SuperCritical Water-cooled Reactor). The mass flux was in the range of 400${\sim}$1200 kg/$m^2$s and the heat flux was chosen up to 150 kW/$m^2$. The selected pressures were 7.75 and 8.12 MPa. The heat transfer data were analyzed and compared with the previous tube test data. The test results showed that the heat transfer characteristics were similar to those of the tube in case of a normal heat transfer mode and degree of heat transfer deterioration became smaller than that in the tube. Comparison of the experimental heat transfer coefficients with the predicted ones by the existing correlations showed that there was not a distinct difference between the correlations.

• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.500-503
• /
• 1997

In this paper, we investigate the control methodology of inverter Airconditioner, using the three dimensional vector scheme. The method of three dimensional vector aims at the determination of optimal switching patterns for PWM to reduce switching loss and to improve the performance supplied voltage. The induction motors are widely used for home Airconditioners. These motors can be classified into two types: on or off control of Airconditioner and the speed control of motor. For speed control of motors, generally PWM methods are used. The PWM method based upon the modulation of triangular wave can not afford to supply line voltage to the motor sufficiently because of the capacity of processing speed of micro processors. Therefore airconditioner can not be operated efficiently. This problem can be solved with the method of three dimensional vector since it can increase the supplied voltage and maximum operating frequency of motor to 173V and 96Hz, respectively. As the result, this method shows 10 - 15% increase of voltage and 10% increase of operating frequency over the modulation of triangular wave. According to a theoretical study, the number of switching in the method of three dimensional vector is smaller than that of the modulation of triangular wave. The power consumption can be reduced and the supplied voltage can be increased. In other words, the efficiency of Airconditioner can be improved. We show that the method of three dimensional vector can supply higher voltage than the modulation of triangular method through the experiments and verify the degree of improvement of efficiency theoretically.

• Journal of ILASS-Korea
• /
• v.25 no.3
• /
• pp.103-110
• /
• 2020

In this study, the behavior of water droplet impacting on a thin horizontal wire was visualized by time-delay photography. The impact behavior modes, critical capture speed and trapped mass were analyzed by changing the droplet size, velocity, wire diameter and eccentricity ratio. As the Weber number increased, the hanging, merging, and splitting modes appeared sequentially for the case of central impact, and the hanging and non-splitting modes appeared for the case of off-center impact. The boundary We number of each mode was affected by the diameter ratio. The critical capture speed was affected much by the degree of eccentricity. For all diameter ratios, it was higher for the case of central impact than for off-center impact. The trapped mass was larger for the case of central impact than for off-center impact and it increased with the smaller We number and the larger diameter ratio.

• Fashion & Textile Research Journal
• /
• v.17 no.5
• /
• pp.815-827
• /
• 2015

This study analyzes the characteristics by age and type for middle aged and elderly women foot shapes aged 40-69 years. ANOVA, factor, and cluster analyzed middle aged and elderly women's foot shapes. The results of the study are as follows. First, higher age groups tended to have smaller foot lengths, ball/instep circumferences, circumferences, and ball heights with larger heel height values and higher degrees of gathering of toe 1 and toe 5 toward the feet reference axis. Second, foot lengths were 220 mm-240 mm and the ball circumference's size symbol in high frequency sections were distributed from E to EEEE in the 40s and 60s groups and from D to EEEE in the 50s group. Third, eight factors were extracted through the factor analyses of middle aged and elderly women's foot measurement items. Fourth, a cluster analyses classified the subjects into four types. Type 1 is a normal foot type with medium foot length and small ball circumference and type 2 is a long and flat foot type with a type with large foot length and ball circumference values as well as small ball height values. Type 3 is a thick foot type with a medium foot length, large ball circumference, large ball height and type 4 is a toe deformation foot type with medium foot length, small ball circumference, and a high degree of toe gathering toward the center.

• Applied Chemistry for Engineering
• /
• v.8 no.5
• /
• pp.771-776
• /
• 1997

The various shape of calcium carbonate were prepared. For the preparation of the PP/$CaCO_3$ composite, these synthetic calcium carbonate(cubic, spheric and neddle type) and PP were mixed on a two roll mill and the mixture were pressed into plate. The effect of particle shape in the prepared composite on the crystallization temperature, heat of fusion, size of spherulite and mechanical properities were investigated. It was found that the former four were strongly influenced by that. When, especially, vaterite was mixed with PP, the size of spherulite was smaller and the degree of crystallinity was higher than others. Therefore, the tensile strength and Young's modulus were higher.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1994.04a
• /
• pp.120-127
• /
• 1994

Noise and vibration induced by subway operation are one of the major factor which annoy residents living near railway tracks. While lateral vibration is a major factor in analyzing seismic effect of the structure, vertical vibration became a major concern in considering the subway induced vibration because relatively smaller energy affects only nearby areas than that of earthquake. A characteristics of structural response induced by subway operation has been studied with different total height of the building and different number of spans. Also the frame with different span length has been studied. As the numbers of degrees freedom increase the higher mode effect on vertical vibration increases. Accordingly, the total affecting vertical modes are distributive as the numbers of degrees of freedom increase. Though the total degree of freedom increases, only some of the dominant modes actively affects to the vertical response of the structure. A frame with the number of equal spans could be analyzed by replacing the whole frame as one when we want to predict the response of the vertical vibration. Also it has been found that the seperate frame analysis will give little different result when adjacent span is relatively longer than others.

• Journal of Korean Academy of Nursing
• /
• v.39 no.3
• /
• pp.393-400
• /
• 2009

Purpose: The purpose of this study was to examine the effects of unilateral sciatic nerve injury on unaffected hindlimb muscles of rats. Methods: Adult male Sprague-Dawley rats were assigned to one of three groups: control(C) group(n=10) that had no procedures, sham(S) group(n=10) that underwent sham left sciatic nerve transection, and sciatic nerve transection(SNT) group(n=9) that underwent left sciatic nerve transection. At 15 days rats were anesthetized, and the soleus, plantaris and gastrocnemius muscles were dissected. Results: Muscle weight of the unaffected plantaris muscle in the SNT group was significantly lower than in the other two groups. Type II fiber cross-sectional areas of the unaffected plantaris and gastrocnemius muscles in the SNT group were significantly smaller than in the other two groups. The decrease of muscle weights and Type I, II fiber cross-sectional areas of the unaffected three muscles in the SNT group were significantly less than that of the affected three muscles. Conclusion: Hindlimb muscle atrophy occurs in the unaffected side after unilateral sciatic nerve injury, with changes in the plantaris and gastrocnemius muscle being more apparent than changes in the soleus muscle. These results have implications for nursing care, in the need to assess degree of muscle atrophy in unaffected muscles as well as affected muscles.

• Carbon letters
• /
• v.19
• /
• pp.89-98
• /
• 2016

Taguchi’s experimental design was employed in the melt spinning of molten mesophase pitch to produce carbon fibers. The textures of the obtained carbon fibers were radial with varied crack angles, as observed by scanning electron microscopy and polarized optical imaging. The diameter, crack angle, preferred orientation, and tensile modulus of the produced samples were examined to investigate the influence of four spinning variables. The relative importance of the variables has been emphasized for each characteristic. The results show that thicker carbon fiber can be obtained with a smaller entry angle, a higher spinning temperature, a reduced winding speed, and an increased extrusion pressure. The winding speed was found to be the most significant factor in relation to the fiber diameter. While it was observed that thicker carbon fiber generally shows improved preferred orientation, the most important variable affecting the preferred orientation was found to be the entry angle. As the entry angle decreased from 120° to 60°, the shear flow was enhanced to induce more ordered radial alignment of crystallite planes so as to obtain carbon fibers with a higher degree of preferred orientation. As a consequence, the crack angle was increased, and the tensile modulus was improved.