• Title/Summary/Keyword: Mass function

Search Result 2,109, Processing Time 0.03 seconds

Dynamical Evolution of Mass Function and Radial Profile of the Globular Cluster System of M87

  • Shin, Ji-Hye;Kim, Sung-Soo S.
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.35 no.1
    • /
    • pp.56.2-56.2
    • /
    • 2010
  • M87, a cD galaxy in the Virgo cluster, has 3-10 times larger enclosed mass than the Milky Way at any given galactocentric radius. Thus the globular cluster (GC) system in M87 is expected to have undergone a more significant dynamical evolution than that of the Milky Way if it had started from the same initial mass function (MF) and radial distribution (RD) as the Milky Way. The evolution of MF and RD of the M87 GC system has been calculated using an advanced, realistic Fokker-Planck (FP) model that considers dynamical friction, disk/bulge shocks, and eccentric cluster orbits. We perform hundreds of FP calculations with different initial cluster conditions, and then search a wide parameter space for the best-fit initial GC MF and RD that evolves into the observed present-day GC MF and RD. We also find best-fit initial MFs and RDs for blue and red GC groups, separately.

  • PDF

Neuropeptidomics: Mass Spectrometry-Based Identification and Quantitation of Neuropeptides

  • Lee, Ji Eun
    • Genomics & Informatics
    • /
    • v.14 no.1
    • /
    • pp.12-19
    • /
    • 2016
  • Neuropeptides produced from prohormones by selective action of endopeptidases are vital signaling molecules, playing a critical role in a variety of physiological processes, such as addiction, depression, pain, and circadian rhythms. Neuropeptides bind to post-synaptic receptors and elicit cellular effects like classical neurotransmitters. While each neuropeptide could have its own biological function, mass spectrometry (MS) allows for the identification of the precise molecular forms of each peptide without a priori knowledge of the peptide identity and for the quantitation of neuropeptides in different conditions of the samples. MS-based neuropeptidomics approaches have been applied to various animal models and conditions to characterize and quantify novel neuropeptides, as well as known neuropeptides, advancing our understanding of nervous system function over the past decade. Here, we will present an overview of neuropeptides and MS-based neuropeptidomic strategies for the identification and quantitation of neuropeptides.

Analysis of Recycle Manufacturing Systems of Assemble Products (조립 제품의 순환형 생산시스템 해석)

  • Ree, Sang-Bok
    • Journal of Korean Institute of Industrial Engineers
    • /
    • v.22 no.3
    • /
    • pp.413-426
    • /
    • 1996
  • Modern society, as a result of high industrial technology, is characterized by a series of mass production, moss consumption and mass disposal. As the mass disposal is known as the major culprit of destroying ecological system of our environment, human prosperity is in turn threatened by this indiscrete activities. Under current industrial technology which pursuit maximum profit, environmental problems could not be solved. This paper proposes recycle manufacturing systems of assemble products as a measure of current non-recycle manufacturing systems. Products are also composed of a number of ports. All parts are represented by a function of time cost performance variable as reuse level. We develop on information systems which give all the information on reused and recycled parts. We try to implement this result on a real fields. We confide ourselves to the contribution to on effective solution of environmental problems and to give profit to assembly manufacturing and consumers.

  • PDF

Modelling of evaporation from free water surface

  • Song, Wei-Kang;Chen, Yibo
    • Geomechanics and Engineering
    • /
    • v.21 no.3
    • /
    • pp.237-245
    • /
    • 2020
  • The process of evaporation from free water surface was simulated in a large scale environmental chamber under various controlled atmospheric conditions and also was modelled by a new mass transfer model. Six evaporation tests were conducted with increasing wind speed and air temperature in the environmental chamber, and hence the effect of atmosphere parameters on the evaporation process and the corresponding response of water were investigated. Furthermore, based on the experiment results, seven general types of mass transfer models were evaluated firstly, and then a new model consisted of wind speed function and air relative humidity function was proposed and validated. The results show that the free water evaporation is mainly affected by the atmospheric parameters and the evaporation rate increases with the increasing air temperature and wind speed. Both the air and soil temperatures are affected by the energy transformation during water evaporation. The new model can satisfactorily describe the evaporation process from free water surface under different atmospheric conditions.

Estimation of Pump Induced Vibration Force Using Transfer Function (전달함수를 이용한 펌프(50Hp)의 진동가진력 산정)

  • 노병철
    • Proceedings of the Earthquake Engineering Society of Korea Conference
    • /
    • 1998.10a
    • /
    • pp.157-162
    • /
    • 1998
  • Dynamic loads may arise from rotating parte of pump if they are insufficiently balanced. The magnitude of pump induced vibrations varies according to the weight, eccentricity, and unbalanced mass of pump. This is a study to estimate the pump induced vibration in time and frequency domain by transfer function. The transfer function has real and imaginary information of signals, and response function has also real and imaginary information. So the vibration force can be obtained from the response and transfer function by complex calculation. The amplitudes and components of 50Hp pump vibration force are suggested.

  • PDF

Obesity and Pulmonary Function in Young Adult Women (20대 여성의 비만과 폐기능에 관한 연구)

  • Chaung, Seung-Kyo
    • Journal of Korean Academy of Fundamentals of Nursing
    • /
    • v.19 no.1
    • /
    • pp.16-22
    • /
    • 2012
  • Purpose: The purpose of this study was to identify Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 Second ($FEV_1$), $FEV_1$/FVC according to obesity in young adult women. Method: Height, weight, body mass index (BMI), and percent body fat (PBF) were obtained by using bioelectrical impedance analysis. Neck circumference (NC), waist circumference (WC) and spirometric values (FVC, $FEV_1$, $FEV_1$/FVC) were obtained for 135 women college students who were healthy and non smokers. Results: Mean BMI and PBF were $21.8kg/m^2$ and 30.5%. Obesity prevalence according to BMI and PBF were respectively 13.3%, and 50.9%. Lean body mass (LBM) was positively correlated with FVC, $FEV_1$, and PBF was negatively correlated with FVC, $FEV_1$ and $FEV_1$/FVC. FVC and $FEV_1$ of the underweight or obese group were lower than those of normal weight group. Conclusion: PBF, but not BMI, is negatively associated with pulmonary function in women college students.

Design of a Linear Mass Excitation System for Simulating Wind-induced Responses of a Building Structure (풍하중 구현 및 내풍특성 평가를 위한 선형질량 가진시스템 설계)

  • Park, Eun-Churn;Lee, Sang-Hyun;Min, Kyung-Won;Kang, Kyung-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2007.11a
    • /
    • pp.661-668
    • /
    • 2007
  • In this paper, excitation systems using linear mass shaker (LMS) are presented in order to simulate the wind induced responses of a building structure. The actuator force for the excitation systems is calculated by using the inverse transfer function of a target structural response to the actuator. Filter and envelop function are used such that the error between the wind and actuator induced responses is minimized by preventing the actuator from exciting unexpected modal response and initial transient response. The analyses results from a 76-story benchmark building problem in which wind load obtained by wind tunnel test is given, indicate that the excitation system installed at a specific floor can approximately embody the structural responses induced by the wind load applied to each floor of the structure. The excitation system designed by the proposed method can be effectively used for evaluating the wind response characteristics of a practical building structure and for obtaining an accurate analytical model of the building under wind load.

  • PDF

Vibration Analysis of Rotating Cantilever Plates with a Concentrated Mass (집중 질량을 가진 회전하는 외팔 평판의 진동 해석)

  • 양정식;유홍희
    • Journal of KSNVE
    • /
    • v.8 no.6
    • /
    • pp.1130-1136
    • /
    • 1998
  • A modelling method for the vibration analysis of rotating cantilever plates with a concentrated mass is presented. The equations of motion for the rotating plates with a concentrated mass located in an arbitrary position are derived and transformed into a dimensionless form. For the mathematical modelling of the concentrated mass. a mass density Dirac delta function is used. The effects of concentrated mass and its location. angular speed. plate aspect ratio. and hub radius of the rotating plate on the natural frequencies are studied. Particularly. mode shape variations due to some parameter variations are investigated.

  • PDF

Optical Determination of the Heavy-hole Effective Mass of (in, Ga)As/GaAs Quantum Wells

  • Lee, Kyu-Seok;Lee, El-Hang
    • ETRI Journal
    • /
    • v.17 no.4
    • /
    • pp.13-24
    • /
    • 1996
  • We determine the reduced mass of heavy-hole exciton and the heavy-hole in-plane mass for a series of (In, Ga)As/GaAs strained layer quantum wells using the magnetolu-minescence measurements of the exciton ground state and the modified perturbation approach. In the theoretical calculation of the magnetoexciton ground state, the exciton reduced mass is considered as an adjustable parameter, and two variation parameters are used in the unperturbed wave function which is expressed in terms of subband wave functions in the growth axis and the product of two-dimensional hydrogen and oscillator like wave functions for the in-plane component. We take into account the energy dependence of transverse and in-plane electron masses in the twoband effective mass approximation. The electron effective mass decreases as either quantum-well width or indium composition increases, and so does the heavy-hole in-plane mass down to the value at the decoupling limit ($m_{hh,\;{\rho}}=0.11m_0$).

  • PDF

Black Hole Binaries Dynamically Formed in Globular Clusters

  • Park, Dawoo;Kim, Chunglee;Lee, Hyung Mok;Bae, Yeong-Bok;Belczynski, Krzysztof
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.42 no.1
    • /
    • pp.43.1-43.1
    • /
    • 2017
  • We investigate properties of black hole (BH) binaries formed in globular clusters, by using direct N-body simulations. Comparing with previous studies which usually considered single BH masses, our models consist of two-component BH masses, or continuous BH mass function with single mass ordinary cluster stars. During the early stage of dynamical evolution, initially distributed BHs are move to the cluster center by dynamical friction, then BH-BH binaries start to be formed, and eventually be ejected from the cluster due to three body interaction. Finally we find the formation efficiency of high mass BHs are alwats larger than that of lower mass BHs, implying that a BH mass spectrum expected from GW observation should be biased to high mass. In addition, mass ratios of BHs in binaries prefer similar masses (ratio~1), while the most extreme case is less than 3. Expected merger rate from our models is about 7 BH-BH mergers per $Mpc^3$ per yr.

  • PDF