• Title/Summary/Keyword: Radius of Gyration

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Targeting of integrin αvβ3 with different sequence of RGD peptides: A molecular dynamics simulation study

  • Azadeh Kordzadeh;Hassan Bardania;Esmaeil Behmard;Amin Hadi
    • Advances in nano research
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    • v.15 no.2
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    • pp.105-111
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    • 2023
  • Integrin αvβ3 is one of the receptors expressed in cancer cells. RGD peptides have the potential to target integrin αvβ3 (receptor), which can increase drug delivery efficiency. In this study, 55 different RGD dimer motifs were investigated. At first, the binding energy between RGD peptides and the receptor was calculated using molecular docking. Then, three RGD peptides with the strongest binding energy with the receptor were selected, and their dynamic adsorption on the receptor was simulated by molecular dynamics (MD). The obtained results showed that a sequence that has RGD at the beginning and end with tryptophan (TRP) has strong Lennard-Jones (LJ) and electrostatic interactions with Integrin αvβ3 and has changed the conformation of receptor significantly, which analyzed by root mean square deviation (RMSD) and radius of gyration.

Emulsion using Biosurfactant as Emulsifier (Biosurfactant를 이용한 유화)

  • 홍세흠;한창규;조춘구
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.25 no.1
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    • pp.137-155
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    • 1999
  • The o/w emulsions were prepared by lysolecithin as a biosurfactantsto to emulsify oils with squalane(SQ), liquid paraffin(LP), octylpalmitate(OP), octylstearate(OS), alkyl benzoate(AB), isostearyl benzoate(ISB). The droplets size and shape of o/w emulsions were investigated by laser light scattering, With dynamic light scattering hydrodynamic radius(Rh) of emulsion droplets was varied from 150m to 250m and critical concentration of oil In which the hydrodynamic radius(Rh) of emulsion droplets decreased and increased was found in the point of 0.5wt% oil concentration, and it was found increasing the polarity of oil deccreased the droplets, the droplets size of SQ(polar oil) were lower than SQ(nonpolar oil) With static light scattering radius of gyration(R$_{g}$) of emulusion droplets was to be calculated. From measurements of the ratio of R$_{g}$R$_{h}$ it was found that the shape of droplet of ISB, AB(polar oils) were sphere, for OP, OS(apolar oil) were oblate, for LP, SQ(nonpolar oil) were rod. The viscosity of emulsion in the form of rod was higher than that of emulsion in the form of sphere.e.e.

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Preset State of Thermoreversible Poly(vinylidene fluoride)/propylene Carbonate Gel System: 1. Core-Shell Model (열가역적인 Poly(vinylidene fluoride)/Propylene Carbonate(PC) 겔 시스템에서의 Pregea 상태 : 1. Core-Shell 모델)

  • 박일현
    • Polymer(Korea)
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    • v.26 no.2
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    • pp.227-236
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    • 2002
  • The structure of pregel state in thermoreversible poly(vinylidene fluoride)(PVDF) /propylene carbonate(PC) system was investigated by laser light scattering. It was found that the PVDF chain did not exist as a separate chain even in a very dilute concentration(i.e. 100 times more dilute than the gel formation concentration) but as a large spherical aggregate with the radius of gyration $R_G$, of 232 nm and the effective hydrodynamic radius $R_H$= of 407 nm at $40^{\circ}C$. Based upon experimental results such as $R_H/R_G$=ratio of 1.75 and the pattern of scattering intensity with a minimum, a core-shell type sphere model was suggested as a structure of the aggregate. According to this model, the radius of core part was estimated as 215 nm, the shell thickness as 192 nm, and the ratio of monomer density of the shell part to that of the core part as about 0.075.

Employing Magnetic Resonance Imaging(MRI) in the Estimation of the Biomechanical Body Segment Parameters of Korean Adults (MRI에 의한 한국인 신체분절의 생체역학적 모수치 산출)

  • Joo, Young-Hwa
    • Korean Journal of Applied Biomechanics
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    • v.12 no.1
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    • pp.233-249
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    • 2002
  • The purpose of this study was to employing MRI in the estimation of the biomechanical body segment parameters of Korean adults. for this purpose MRI study on 19 Korean living subjects were used to measurement. All the parameters that was concerned were inertial characteristics of human body mass of each segment, center of mass of them and the length of radius of gyration of them. The cross sectional images and saggital images of every 1cm interval were got using the 0.5 Tesla MRI from the top of head to the bottom of foot, whole body. And then, by tracing the images of the film and scanning them, got the area which the several tissues occupied in the image of slice. By summing the area of slice of each segment which were calculating and by multipling the density of the tissues, got the mass of segment and other inertial characteristics. The ratios of radius of gyration in both transverse axis and longitudinal axis though the segmental mass and segment length are as follow: male A : head($0.229\pm0.0029$), neck($0.256\pm0.0095$), thorax($0.374\pm0.0059$) abdomen($0.245\pm0.0020$), pelvis($0.368\pm0.0106$), thigh($0.288\pm0.0030$) shank($0.280\pm0.0043$), foot($0.277\pm0.0195$), upperarm($0.311\pm0.0074$) forearm($0.286\pm0.0051$), hand($0.253\pm0.0095$) female A : head($0.214\pm0.0032$), neck($0.254\pm0.0112$), thorax($0.295\pm0.0061$) abdomen($0.289\pm0.0021$), pelvis($0.329\pm0.0108$), thigh($0.288\pm0.0036$) shank($0.280\pm0.0047$), foot($0.243\pm0.0206$), upperarm($0.279\pm0.0083$) forearm($0.286\pm0.0048$), hand($0.229\pm0.0097$) male B : head($0.532\pm0.0006$), neck($0.533\pm0.0006$), thorax($0.658\pm0.0008$) abdomen($1.350\pm0.0022$), pelvis($0.875\pm0.0002$), thigh($0.213\pm0.0001$) shank($0.160\pm0.0001$), foot($0.152\pm0.0002$), upperarm($0.136\pm0.0002$) forearm($0.202\pm0.0002$), hand($0.273\pm0.0006$) female B : head($0.198\pm0.0002$), neck($0.335\pm0.0011$), thorax($0.238\pm0.0001$) abdomen($0.888\pm0.0001$), pelvis($1.318\pm0.0117$), thigh($0.095\pm0.0001$) shank($0.075\pm0.0001$), foot($0.181\pm0.0006$), upperarm($0.0.062\pm0.0001$) forearm($0.083\pm0.0001$), hand($0.105\pm0.0007$).

Aeroelastic stability analysis of a two-stage axially deploying telescopic wing with rigid-body motion effects

  • Sayed Hossein Moravej Barzani;Hossein Shahverdi
    • Advances in aircraft and spacecraft science
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    • v.10 no.5
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    • pp.419-437
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    • 2023
  • This paper presents the study of the effects of rigid-body motion simultaneously with the presence of the effects of temporal variation due to the existence of morphing speed on the aeroelastic stability of the two-stage telescopic wings, and hence this is the main novelty of this study. To this aim, Euler-Bernoulli beam theory is used to model the bending-torsional dynamics of the wing. The aerodynamic loads on the wing in an incompressible flow regime are determined by using Peters' unsteady aerodynamic model. The governing aeroelastic equations are discretized employing a finite element method based on the beam-rod model. The effects of rigid-body motion on the length-based stability of the wing are determined by checking the eigenvalues of system. The obtained results are compared with those available in the literature, and a good agreement is observed. Furthermore, the effects of different parameters of rigid-body such as the mass, radius of gyration, fuselage center of gravity distance from wing elastic axis on the aeroelastic stability are discussed. It is found that some parameters can cause unpredictable changes in the critical length and frequency. Also, paying attention to the fuselage parameters and how they affect stability is very important and will play a significant role in the design.

A study on simulation technic of a complex movement of the end of cars on a rail track using CATIA V5 (CATIA V5를 이용한 선로위의 철도 차량 끝단 부의 복합적인 움직임을 가시화하는 시뮬레이션 방법 연구)

  • Shin, In-Su;Yun, Gi-Seok;Lee, Ha-Hee;Ryu, Hyeon-Gyu
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.979-983
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    • 2010
  • In case a set of railway vehicles moves on a rail track, the end of each car in which a coupler is installed produces a complex movement depending on the displacement of a rail track, bogie and a coupler. Especially, the movement of an end of cars is hugely affected by a radius of gyration and gradient of a rail track, vertical and lateral movement of bogie, and compression of coupler. In this thesis, I present a simulation technic for easy input and change of displacement of a rail track, bogie and a coupler as well as visualization of movement of the end of cars on a rail track using CATIA V5, CAD software.

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Out-of-plane buckling and bracing requirement in double-angle trusses

  • Chen, Shaofan;Su, Mingzhou
    • Steel and Composite Structures
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    • v.3 no.4
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    • pp.261-275
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    • 2003
  • Truss members built-up with double angles back-to-back have monosymmetric cross-section and twisting always accompanies flexion upon the onset of buckling about the axis of symmetry. Approximate formulae for calculating the buckling capacity are presented in this paper for routine design purpose. For a member susceptible only to flexural buckling, its optimal cross-section should consist of slender plate elements so as to get larger radius of gyration. But, occurrence of twisting changes the situation owing to the weakness of thin plates in resisting torsion. Criteria for limiting the leg slenderness are discussed herein. Truss web members in compression are usually considered as hinged at both ends for out-of-plane buckling. In case one (or both) end of member is not supported laterally by bracing member, its adjoining members have to provide an elastic support of adequate stiffness in order not to underdesign the member. The stiffness provided by either compression or tension chords in different cases is analyzed, and the effect of initial crookedness of compression chord is taken into account. Formulae are presented to compute the required stiffness of chord member and to determine the effective length factor for inadequately constrained compressive diagonals.

Effects of Engine Loads on Exhaust Emissions and Particulate Matter with Morphological Characteristics in a Common Rail 4 Cylinder Diesel Engine

  • Roh, Hyun-Gu;Choi, Seuk-Cheun;Lee, Chang-Sik
    • Journal of the Korean Society of Combustion
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    • v.15 no.3
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    • pp.57-66
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    • 2010
  • The purpose of this paper is to investigate the effects of fuel injection strategy and engine load on the structure and emissions characteristics of a DI diesel engine with 1.6L of piston displacement. In order to analyze the particulate matter (PM) and exhaust emissions characteristics in a direct injection diesel engine, the quantity of PM and exhaust emissions (including HC, CO and $NO_X$) were investigated under various injection strategies and engine loads. Two different injection strategies (one pilot/main injection and two pilots/main injection) was investigated under the various engine loads. A thermophoretic sampling method with a scanning electron microscope (SEM) were used to obtain the PM morphology (including primary particles, the size of the agglomerates, the number of agglomerates, the fractal dimension). The quantity of soot gradually increased with increasing engine load at both injection strategies. The primary particles in the PM agglomerates indicate that the average of the primary particle and radius of gyration increased as the engine load increased.

Steering System in a Self-Balancing Electric Scooter (역진자형 전동 스쿠터의 조향 시스템)

  • Choi, Yong Joon;Ryoo, Jung Rae;Doh, Tae-Yong
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.9
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    • pp.942-949
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    • 2014
  • In this paper, a new steering system for a self-balancing electric scooter is proposed with an intuitive steering command input method, where the steering command is generated from the rider's motion of shifting body to move the center of gravity toward the rotational direction. For the purpose, weight distributions on the rider's feet are measured using force sensors placed beneath the rider's feet, and the difference is applied to a steering control system. Stability of the steering system and resultant radius of gyration is investigated by modeling the steering system in consideration of the rider's motion and centrifugal force. The proposed steering system is applied to experiments, and the results are presented to prove the validity of the proposed method.

Coil-to-globule transition of thermo-responsive γ-substituted poly (ɛ-caprolactone) in water: A molecular dynamics simulation study

  • Koochaki, Amin;Moghbeli, Mohammad Reza;Nikkhah, Sousa Javan
    • Current Applied Physics
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    • v.18 no.11
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    • pp.1313-1319
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    • 2018
  • The coil-to-globule behavior of poly{${\gamma}$-2-[2-(2methoxyethoxy)ethoxy]ethoxy-3-caprolactone} (PMEEECL) as a ${\gamma}$-substituted poly (${\varepsilon}$-caprolactone) was investigated via atomistic molecular dynamics (MD) simulation. For this purpose, radius of gyration, end-to-end distance and radial distribution function of the chain in the presence of water were calculated. Consequently, the lower critical solution temperature (LCST) of PMEEECL chain at which the coil-to-globule transition takes place, was determined in each calculated parameter curve. The simulation results indicated that the LCST of PMEEECL was occurred at close to 320 K, which is in a good agreement with previous experimental results. Additionally, the appearance of sudden change in both Flory-Huggins interaction parameter (${\chi}$) and interaction energy between the PMEEECL chain and water molecules at about 320 K confirmed the calculated LCST result. The radial distribution function (RDF) results showed that the affinity of the PMEEECL side chain to water molecules is lower than its backbone.