• Title, Summary, Keyword: relative frequencies

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Immunohistochemical study on the insulin-immunoreactive cells in the developing pancreas of the Korean native goat (Capra hircus)

  • Ku, Sae-kwang;Lee, Hyeung-sik;Lee, Jae-hyun
    • Korean Journal of Veterinary Research
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    • v.39 no.4
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    • pp.673-678
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    • 1999
  • The distribution and relative frequency of insulin-immunoreactive cells in the pancreas was studied during developmental stages (fetus, neonate, 1-month-old, 6-month-old and adult) of the Korean native goat by immunohistochemical methods. The different distribution and relative frequency of glucagon-immunoreactive cells in the pancreas of the Korean native goat was observed during development. Insulin-immunoreactive cells were detected in the exocrine and endocrine portions (pancreatic islets) of the all ages, and in the duct of the 6-month-old. The relative frequencies of these cells were increased in the pancreatic islets with ages but decreased in the exocrine portions. Generally, they were distributed in the interacinar spaces or central zone of the pancreatic islets in all ages. However, the distributions and relative frequencies in the pancreatic islets of the neonate Korean native goat were divided into three patterns : 1) located in the inner zone with numerous frequencies, 2) the peripheral zone of the pancreatic islet with moderate frequencies and 3) the peripheral zone of the pancreatic islet with a few frequencies patterns.

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Changes of the Somatostatin-immunoreactive Cells in the Pancreas of the Korean Native Goat (Capra hircus) during Development

  • Sae-Kwang Ku;Ki-dae Park;Hyeung-Sik Lee;Jae-Hyun Lee
    • Animal cells and systems
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    • v.3 no.3
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    • pp.269-273
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    • 1999
  • The distribution and relative frequency of somatostatin-immunoreactive cells in the pancreas were studied during developmental stages (fetus, neonate, 1-month-old, 6-month-old and adult) of the Korean native goat by immunohistochemical methods. Somatostatin-immunoreactive cells were detected in the exocrine of all ages, in the endocrine portions (pancreatic islets) from the neonate, and in the pancreatic duct of the 1-month-old. The relative frequencies of these cells in the pancreatic islets increased with age. However, there were no age-related changes in the relative frequencies of somatostatin-immunoreactive cells in the exocrine and pancreatic duct. Generally, they were distributed in the interacinar spaces, the epithelium of the pancreatic duct, or dispersed in the peripheral zone of the pancreatic islets in all ages. However, clusters consisting of 3-4 cells were also found in the subepithelial connective tissues from the 1-month-old. In addition, the distributions in the endocrine portions of the adult were divided into two patterns: 1) they are dispersed in the marginal regions with moderate or low frequencies, or 2) in the inner zone with high frequencies.

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Ab Initio Quantum Mechanical Investigation of H2(An+1X2n)H2(A=C or Si, X=O or S, n = 1-2)]; Energetics, Molecular Structures, and Vibrational Frequencies

  • Choi, Kun-Sik;Kim, Hong-Young;Kim, Seung-Joon
    • Bulletin of the Korean Chemical Society
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    • v.26 no.1
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    • pp.119-126
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    • 2005
  • The geometrical parameters, vibrational frequencies, and relative energies of H$_2$(A$_{n+1}$X$_{2n}$)H$_2$ (A=C or Si, X=O or S, n = 1-2) oligomers have been investigated using high level ab initio quantum mechanical techniques with large basis sets. The equilibrium geometries have been optimized at the self-consistent field (SCF), the coupled cluster with single and double excitation (CCSD), and the CCSD with connected triple excitations [CCSD(T)] levels of theory. The highest level of theory employed in this study is cc-pVTZ CCSD(T). Harmonic vibrational frequencies and IR intensities are also determined at the SCF level of theory with various basis sets and confirm that all the optimized geometries are true minima. Also zero-point vibrational energies have been considered to predict the dimerization and the relative energies.

A Study on Absorption Properties of the EM Wave Absorber Using TiO2 in W-band

  • Choi, Chang-Mook;Ko, Kwang-Soob
    • Journal of Navigation and Port Research
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    • v.34 no.2
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    • pp.111-115
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    • 2010
  • In this paper, the electromagnetic (EM) wave absorbers using TiO2 as a dielectric material with chlorinated polyethylene (CPE) were investigated in W-band radio frequencies. We compared the relative permittivity with reflectionless curve and the absorption properties of samples containing 40 wt.%, 50 wt.%, 60 wt.%, 70 wt.%, and 80 wt.% TiO2. It is possible to realize a complex relative permittivity satisfying the reflectionless condition by choosing composition ratio of TiO2. The optimized composition ratio of TiO2 for the maximum absorption property is about 70 wt.%. As a result, we have confirmed the realization of an EM wave absorber with a high absorption property in W-band radio frequencies.

The Frequencies and Disease-Association of HLA Alleles in Bipolar Patients (양극성 장애환자에서 HLA 대립형의 빈도와 질병연관성)

  • Jun, Tae-Youn
    • Korean Journal of Biological Psychiatry
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    • v.1 no.1
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    • pp.79-87
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    • 1994
  • For the purpose of evaluating the human leukocyte antigen(HLA) disease-association with bipolar disorder, HLA class I and class II allelic frequencies were assessed in 37 bipolar patients and were compared to the data from normal population. HLA class 1 typing was performed with microlymphocytotoxicity method while class II(DRB1) genotyping with reverse dot blot hybridization and sandwich method. Statistical analysis consisted of relative risk, Haldane's modified relative risk, Fisher's exact test and Bonferoni's corrected P. The results were as follows : 1) Bipolar patients showed increased allelic frequency of HLA A3 which has statistical significance. 2) Allelic frequencies of HLA B7, B14 and B54 were higher, while those of B51 and B55 were lower in bipolar patients, but they were not statistically significant. 3) Both of increased frequencies of DR2 in bipolar patients and DR15 in normal controls had statistical significance. The results of the present study suggested that some of HLA allelic types might be associated with bipolar disorder. To clarify the genetic influence of HLA to bipolar disorder, we should do consecutive study of bipolar disorder with new information about HLA system including alleles.

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Dual-Band Circularly Polarized Stack-Ring Antenna

  • Sung, Youngje
    • Journal of electromagnetic engineering and science
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    • v.19 no.1
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    • pp.37-41
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    • 2019
  • A stack-ring configuration is proposed for designing a dual-band circularly polarized (CP) antenna. Each ring generates different resonant frequencies. A good CP performance at both resonant frequencies is achieved by adjusting the relative distance between the two rings. The two operating bands are separated with a small frequency ratio of 1.07. Measured results show that radiation patterns with good CP characteristics are obtained at the two resonant frequencies.

A Comparison of Surge Behaviors in Multi-Stage and Single-Stage Axial Flow Compressors

  • Yamaguchi, Nobuyuki
    • International Journal of Fluid Machinery and Systems
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    • v.9 no.4
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    • pp.338-353
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    • 2016
  • Information on the surge behaviors and stall stagnation boundaries for a nine-stage axial flow compressor are summarized on the basis of analytical data in comparison with those for a single-stage one, with attention to the pressure ratio effect. The general trends of the surge loop behaviors of the pressure-mass flow are similar for both compressors including the fact that the subharmonic surges tend to appear very near the stall stagnation boundaries. With respect to the nine-stage compressor, however, the mild loops in the subharmonic surges tend to be very small in size relative to the deep loops, and at the same time, insufficient surge recovery phenomenon, which is a kind of subharmonic surge, appears also far from the stagnation boundary for relatively short delivery flow-paths. The latter is found to be a rear-stage surge caused by unstalling and re-stalling of the rear stages with the front-stages kept in stall in the stalled condition of the whole compressor, which situation is caused by stage-wise mismatching in the bottom pressure levels of the in-stall multi-stage compressor. The fundamental information on the stall stagnation boundaries is given by a group of normalized geometrical parameters including relative delivery flow-path length, relative suction flow-path length, and sectional area-pressure ratio, and by another group of normalized frequency parameters including relative surge frequencies, modified reduced resonance frequencies, and modified reduced surge frequencies. Respective groups of the normalized parameters show very similar tendency of behaviors for the nine-stage compressor and the single-stage compressor. The modified reduced resonance frequency could be the more reasonable parameter suggesting the flow-induced oscillation nature of the surge phenomena. It could give the stall stagnation boundary in a more unified manner than the Greitzer's B parameter.

Development of Monitoring and Diagnosis System for Linear Motion Unit (직선 운동 유닛의 감시 및 진단 시스템 개발)

  • Huang, Jian;Kim, Hwa-Young;Ahn, Jung-Hwan
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.635-636
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    • 2012
  • In the present work, investigations by high frequency resonance technique for diagnosis of defect frequencies of linear motion unit are reported. Raw vibration signature of the moving parts at different speeds of operation has been demodulated. Envelope detected spectrum is analyzed to evaluate various defect frequencies and their energy levels. Experimentally evaluated frequencies are compared with theoretically determined defect frequencies. These frequency values and their energy levels are used to monitor intrinsic condition of linear motion unit as well as to establish severity of existing/developed defects on the LM guide and inside the LM block. Relative comparisons of linear motion units of the same type are made at various operating speeds under identical conditions of operation on the basis of identified defect frequencies and severity of defects.

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Damage detection of mono-coupled multistory buildings: Numerical and experimental investigations

  • Xu, Y.L.;Zhu, Hongping;Chen, J.
    • Structural Engineering and Mechanics
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    • v.18 no.6
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    • pp.709-729
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    • 2004
  • This paper presents numerical and experimental investigations on damage detection of mono-coupled multistory buildings using natural frequency as only diagnostic parameter. Frequency equation of a mono-coupled multistory building is first derived using the transfer matrix method. Closed-form sensitivity equation is established to relate the relative change in the stiffness of each story to the relative changes in the natural frequencies of the building. Damage detection is then performed using the sensitivity equation with its special features and minimizing the norm of an objective function with an inequality constraint. Numerical and experimental investigations are finally conducted on a mono-coupled 3-story building model as an application of the proposed algorithm, in which the influence of modeling error on the degree of accuracy of damage detection is discussed. A mono-coupled 10-story building is further used to examine the capability of the proposed algorithm against measurement noise and incomplete measured natural frequencies. The results obtained demonstrate that changes in story stiffness can be satisfactorily detected, located, and quantified if all sensitive natural frequencies to damaged stories are available. The proposed damage detection algorithm is not sensitive to measurement noise and modeling error.

Effects of prestressing force on natural frequency of prestressed concrete beams considering self-weight

  • Shin, Soobong;Lee, Hokyoung;Lee, Jong-Han
    • Structural Engineering and Mechanics
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    • v.74 no.4
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    • pp.495-502
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    • 2020
  • This study investigated the effects of prestressing force on the natural frequency of concrete beams considering changes in the self-weight of the beam. For this, a finite element formulation was derived to account for the increase in the stiffness of a beam-tendon system due to the axial force and deformation induced by prestressing of the tendon. The developed finite element formulation was validated with the data obtained in laboratory experiments. The experimental natural frequencies of the small prestressed concrete (PSC) beam specimens were consistent with those obtained using the proposed method. The first natural frequency increased almost linearly as the prestressing force increased. The proposed method was then applied to four actual PSC bridges typically employed in the field. Different from the laboratory specimens, the first natural frequencies of the actual PSC bridges barely changed or increased with increasing prestressing force. The results of an analytical parametric study showed that the increase in the natural frequency strongly depended on the magnitude of the prestressing force relative to the total weight of the structure. Thus, the variation in the natural frequencies of the actual PSC bridges with high total weight relative to the prestressing force was negligible due to the application of the prestressing force.