• Title/Summary/Keyword: physical length

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Threshold Subsoil Bulk Density for Optimal Soil Physical Quality in Upland: Inferred Through Parameter Interactions and Crop Growth Inhibition

  • Cho, Hee-Rae;Han, Kyung-Hwa;Zhang, Yong-Seon;Jung, Kang-Ho;Sonn, Yeon-Kyu;Kim, Myeong-Sook;Choi, Seyeong
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.5
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    • pp.548-554
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    • 2016
  • Optimal range of soil physical quality to enhance crop productivity or to improve environmental health is still in dispute for the upland soil. We hypothesized that the optimal range might be established by comparing soil physical parameters and their interactions inhibiting crop growth. The parameter identifying optimal range covered favorable conditions of aeration, permeability and root extension. To establish soil physical standard two experiments were conducted as follows; 1) investigating interactions of bulk density and aeration porosity in the laboratory test and 2) determining effects of soil compaction and deep & conventional tillage on physical properties and crop growth in the field test. The crops were Perilla frutescens, Zea mays L., Solanum tuberosum L. and Secale cereael. The saturated hydraulic conductivity, bulk density from the root depth, root growth and stem length were obtained. Higher bulk density showed lower aeration porosity and hydraulic conductivity, and finer texture had lower threshold bulk density at 10% aeration bulk density. Reduced crop growth by subsoil compaction was higher in silt clay loam compared to other textures. Loam soil had better physical improvement in deep rotary tillage plot. Combined with results of the present studies, the soil physical quality was possibly assessed by bulk density index. Threshold subsoil bulk density as the upper value were $1.55Mg\;m^{-3}$ in sandy loam, $1.50Mg\;m^{-3}$ in loam and $1.45Mg\;m^{-3}$ in silty clay loam for optimal soil physical quality in upland.

The changes of rectus abdominis muscle thickness according to the angle during active straight leg raise

  • Lee, Hwang Jae;Shin, Kil Ho;Byun, Sung Mi;Jeong, Hyeon Seo;Hong, Ji Su;Jeong, Su Ji;Lee, Wan Hee
    • Physical Therapy Rehabilitation Science
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    • v.2 no.1
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    • pp.44-48
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    • 2013
  • Objective: The purpose of this study was to investigate changes of abdominal muscles thickness according to the angle during the active straight leg raise (ASLR) in young healthy subjects. Design: Cross sectional study. Methods: Twenty-three healthy university students (13 men and 10 women) voluntary participated to the study in S University. The ASLR was performed with the subject lying supine with lower extremities straight on a standard plinth, hands resting on the chest, and elbows on the plinth. When one subject performed ASLR from each angles ($30^{\circ}$, $45^{\circ}$, $60^{\circ}$, $90^{\circ}$), compared changes in the thickness of rectus abdominis muscle. Changes in muscle thickness during ASLR test were assessed with ultrasonography. All subjects were to provide enough time of rest after performed ASLR. Rectus abdominis thickness were measured using rehabilitative ultrasound image. Results: Good quality rectus abdominal muscle activation data were recorded during ASLR. The length changes of linea alba showed significantly shorter in between $0^{\circ}$ and $30^{\circ}$ (p<0.05). The thickness of rectus abdominis muscle were significantly different between $0^{\circ}$ and $30^{\circ}$, $0^{\circ}$ and $45^{\circ}$, $0^{\circ}$ and $60^{\circ}$, $0^{\circ}$ and $90^{\circ}$. According to increase of pelvic angle, the thickness of rectus abdominis muscle were more thickening (p<0.05). Conclusions: This result is changes of abdominal muscles thickness according to the angle during the ASLR.

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Effects of Elastic Taping and Non-elastic Taping on Static Balance Control Ability, Dynamic Balance Control Ability, and Navicular bone Drop in Young Adults

  • Lim, Jong-Gun;Lee, Hyun-Woo;Lee, Dongyeop;Hong, Ji-Heon;Yu, Jae-Ho;Kim, Jin-Seop;Kim, Seong-Gil
    • Journal of the Korean Society of Physical Medicine
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    • v.17 no.2
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    • pp.1-10
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    • 2022
  • PURPOSE: This study examined the effects of the low dye taping technique on the static and dynamic balancing ability and navicular bone drop when the low dye taping technique was divided into elastic and non-elastic taping. METHODS: The subjects of the study were 31 volunteers without musculoskeletal disorders. The length (L) and anterior (A), posteromedial, and posterolateral values of the arch in the NO (normal eyes open), NC (normal eyes closed), PO (pillow with eyes open), and PC (pillow with close eyes closed) states were evaluated when barefoot and when Kinesio tape and non-elastic tape were applied. The measurements were analyzed using repeated ANOVA and an independent t-test. Post hoc tests were performed using a Fisher's LSD. RESULTS: A significant difference was found in the arch L and A values using a foot scanner (p < .05). In addition, there was a significant difference in dynamic balance in the three directions (p < .05), and no difference was found in the case of static balance. As a result, non-elastic tape application helps improve the dynamic balance ability and arch of the foot. CONCLUSION: The non-elastic tape technique is helpful for the foot arch function, and there is no difference in the static balance ability between Kinesio tape and non-elastic tape. Nevertheless, non-elastic tape is more helpful for the dynamic balance ability than Kinesio taping.

Biosynthesis, Modification, and Biodegradation of Bacterial Medium-Chain-Length Polyhydroxyalkanoates

  • Kim, Do-Young;Kim, Hyung-Woo;Chung, Moon-Gyu;Rhee, Young-Ha
    • Journal of Microbiology
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    • v.45 no.2
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    • pp.87-97
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    • 2007
  • Medium-chain-length polyhydroxyalkanoates (MCL-PHAs), which have constituents with a typical chain length of $C_{6}-C_{14}$, are polyesters that are synthesized and accumulated in a wide variety of Gram-negative bacteria, mainly pseudomonads. These biopolyesters are promising materials for various applications because they have useful mechanical properties and are biodegradable and biocompatible. The versatile metabolic capacity of some Pseudomonas spp. enables them to synthesize MCL-PHAs that contain various functional substituents; these MCL-PHAs are of great interest because these functional groups can improve the physical properties of the polymers, allowing the creation of tailor-made products. Moreover, some functional substituents can be modified by chemical reactions to obtain more useful groups that can extend the potential applications of MCL-PHAs as environmentally friendly polymers and functional biomaterials for use in biomedical fields. Although MCL-PHAs are water-insoluble, hydrophobic polymers, they can be degraded by microorganisms that produce extracellular MCL-PHA depolymerase. MCL-PHA-degraders are relatively uncommon in natural environments and, to date, only a limited number of MCL-PHA depolymerases have been investigated at the molecular level. All known MCL-PHA depolymerases share a highly significant similarity in amino acid sequences, as well as several enzymatic characteristics. This paper reviews recent advances in our knowledge of MCL-PHAs, with particular emphasis on the findings by our research group.

A Classification of Somatotypes of Korean Males in Thirties(Part I) - Focused on the Upper Body -

  • Kim, Jin-Sun;Shim, Kue-Nam;Lee, Won-Ja
    • The International Journal of Costume Culture
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    • v.4 no.2
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    • pp.77-85
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    • 2001
  • The purpose of this study was to classify the somatotype around a upper body of 30's men. The subjects were 202 working men aged from 30 to 39 and the data of 33 items including computed items were analysed by factor analysis and cluster analysis. Re results were as follows: As a factor of somatotype in evaluating males in 30's, the horizontal area represented the chest circumference at scye and the breadth items, the vortical region indicated hit length posterior, front length, back length, the breadth difference and the length difference. The somatotype by cluster analysis was classified with 3 type. Type I as the Roher's index 1.21 indicating the smallest in the circumference and weight item was classified as the thin and long featuring bending somatotype. Type 2 with the Rohrer's index 1.35 showing the mid-group between type 1 and 3 had the highest distribution rate as the balanced featuring the standard somatotype. Type 3 as the rohrer's index 1.40 was the largest physical condition group in the obesity featuring the turning over somatotype.

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Minimizing Design of the Schiffman Phase Shifter Using the Defected Ground Structure (결함접지면을 이용한 쉬프만 위상 천이기의 소형화)

  • Kim, Gi-Rae
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.9
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    • pp.1745-1752
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    • 2009
  • This Paper represents a new method, which uses defected ground structure (DGS) on the ground planes of microstrip lines, to reduce the size of the Schiffman phase shifter. DGS on the microstrip line shows an increased slow-wave effect due to the additional equivalent L and C components. So the electrical length of transmission line with DGS is longer than that of standard transmission line for the same physical length. Then, the length of transmission line with DGS can be shortened in order to maintain the original electrical length to be same. The performances of reduced phase shifter with DGS are quite similar to the ones of original Schiffman phase shifters. We can reduce the size about 15% using the DGS in original Schiffman phase shifter.

Shear Performance of Wood-Concrete Composite II - Shear Performance with Different Anchorage Length of Steel Rebar in Concrete -

  • Lee, Sang-Joon;Eom, Chang-Deuk;Kim, Kwang-Mo
    • Journal of the Korean Wood Science and Technology
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    • v.40 no.5
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    • pp.327-334
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    • 2012
  • Wood and concrete show significantly different physical properties, and it need to be firstly understood for using wood-concrete composite. This study is performed for compensating this and effective hybridization of wood and concrete. This research in planned for wood-concrete composite after previous research which deals the shear performance with different anchorage length of steel rebar in wood. Yield mode and reference design value (Z) were derived using EYM (European Yield Model). And the yield mode changed before and after anchorage length of 10~15 mm - $I_s$ mode to IV mode. There was not increasing tendency of shear performance with increased anchorage length for over 20 mm of anchorage in concrete. And wood composite shows 65% and 93% on initial stiffness and yield load respectively compared with the wood-concrete composite. Wood-concrete composite showed brittle failure after yield point while wood-to-wood composite showed ductile failure.

Effect of Weight Loads Applied to the Ankle on Walking Factors of a Stroke Patient (발목에 적용한 무게 부하가 뇌졸중 환자의 보행요소에 미치는 영향)

  • Lee, Su-Kyoung
    • PNF and Movement
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    • v.16 no.2
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    • pp.179-185
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    • 2018
  • Purpose: This study aimed to analyze the visual and spatial elements of the gait of a stroke patient who had diverse ankle weight loads applied, according to weight changes. Methods: The subject was a 57-year-old stroke patient diagnosed and hospitalized with a left intracerebral hemorrhage. A weight equivalent to 0%, 1%, and 2% of his body weight was applied to the area 5cm upward from the ankle using a Velcro strap. He was then trained on a treadmill, receiving a six-minute walk test to evaluate his gait ability. A gait analyzer was used to collect visual and spatial elements, such as gait distance, gait velocity, cadence, step length, stride length, and swing phase, according to a weight load equivalent to 0%, 1%, and 2% of his body weight. Results: According to the results of applying 0%, 1%, and 2% of his body weight on the ankle, except for gait velocity, his gait distance, cadence, step length, stride length, and swing phase were higher when 1% of his body weight was applied compared to 0% or 2% of his body weight. Conclusion: Applying a weight equivalent to 1% of the body weight to the ankle positively affected the visual and spatial element of the gait and heightened the efficiency of exercise during treadmill training, a gait-training tool generally used for stroke patients. However, the result is difficult to generalize because the number of subjects was small with only one subject.

A Study on the Threshold Condition of Crack Propagation for Pre-Crack and Micro-Hole Specimens (프리크랙과 微小圓孔材의 크랙成長 下限界條件에 관한 硏究)

  • 송삼홍;윤명진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.2
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    • pp.278-285
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    • 1988
  • The Critical size of artificially induced micro-holes in 0.17%, 0.36% Carbon steel Specimens with Spheroidized Cementite and in 0.17% carbon steel specimens with martensite structure is compared with annealed pre-crack in order to discuss the physical meaning of the fatigue limit and evaluation of the tolerant micro flaw size at the stress level of the fatigue limit. Results obtained were summarized as follows; (1) In this study, non-propagating crack length of Smooth specimen and critical pre-crack length (lc) is coincide. (2) In the carbon steels with spheroidized cementite structure, critical pre-crack length (lc) and allowable micro-hole size (dc) is coincide each other at the fatigue limit level. (3) It has been published that there exists a particular size of micro-hole which has no effect on the fatigue limit. In this study, the micro-hole of critical size can be regarded as equivalent to a tolerant micro flaw which would not reduce the fatigue limit.

The effects of the different steps on the forces and moments of the lower extremity's joint in the three dimension during a steady running (달리기 시 일정한 속도에서 보폭 차이가 하지 관절의 3차원 힘과 모멘트에 미치는 영향)

  • Ryu, Ji-Seon
    • Korean Journal of Applied Biomechanics
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    • v.12 no.1
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    • pp.47-61
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    • 2002
  • The purpose of this study was to determined the force and moment of the ankle and the knee joint at different step length relative to the length of the lower extremity during a steady running. Six digital cameras(Qualisis) and a forceplatform(A.M.T.I) were used to obtain the kinematic data of the segments and kinetic data on the running at speed of 5.18m/s. The force and moment measured from six subjects participated in this study were limited to the support phase and their values were averaged at the moment of heel strike, mid stance, and toe off of a running for making a comparison between the condition 1(relative step length 1.1) and the condition 2(relative step length 1.4). It was concluded that internal forces except mediolateral force of the condition 2 were greater in the ankle and the knee joint than those of the condition 1, but all moments of condition 2 were greater from the descriptive statistic point of view. For the future study, it was needed to consider a number of subjects, a various running speed, and a individual step preference for applying generally results to the running strategy.