24 research outputs found
Dynamics of asteroid systems post-rotational fission
publishedVersio
Extended two-body problem for rotating rigid bodies
A new technique that utilizes surface integrals to find the force, torque and
potential energy between two non-spherical, rigid bodies is presented. The
method is relatively fast, and allows us to solve the full rigid two-body
problem for pairs of spheroids and ellipsoids with 12 degrees of freedom. We
demonstrate the method with two dimensionless test scenarios, one where
tumbling motion develops, and one where the motion of the bodies resemble
spinning tops. We also test the method on the asteroid binary (66391) 1999 KW4,
where both components are modelled either as spheroids or ellipsoids. The two
different shape models have negligible effects on the eccentricity and
semi-major axis, but have a larger impact on the angular velocity along the
-direction. In all cases, energy and total angular momentum is conserved,
and the simulation accuracy is kept at the machine accuracy level.Comment: 24 pages, 9 figures, accepted for publication in Celestial Mechanics
and Dynamical Astronom
The effect of excipients on the stability and aerosol performance of salmon calcitonin dry powder inhalers prepared via spray freeze drying process
Spray freeze drying was developed to produce dry powders suitable for applications such as inhalation delivery. In the current study, the spray freeze drying technique was employed to produce inhalable salmon calcitonin microparticles. Effects of the carrier type, concentration of hydroxyl propyl-β-cyclodextrin and the presence of Tween 80 on the chemical and structural stability, as well as on the aerosol performance of the particles were investigated. The results indicated that hydroxyl propyl-β-cyclodextrin had the most important effect on the chemical stability of the powder and strongly increased its stability by increasing its concentration in the formulation. Chemically stable formulations (over 90 % recovery) were selected for further examinations. Fluorescence spectroscopy and circular dichroism suggested that the formulations were structurally stable. Aerosol performance showed that the Tween-free powders produced higher fine particle fraction values than the formulations containing Tween (53.7 vs. 41.92 % for trehalose content and 52.85 vs. 43.06 % for maltose content)
DETC2009-87585 DRAFT: LOGARITHMIC COMPLEXITY SENSITIVITY ANALYSIS OF FLEXIBLE MULTIBODY SYSTEMS
ABSTRACT This paper presents a recursive direct differentiation metho
Targeted Reinforcement of Macrophage Reprogramming Towards M2 Polarization by IL-4 Loaded Hyaluronic Acid Particles
Correction: ACS Omega 2019, 4, 3, 5931-5931 DOI: 10.1021/acsomega.9b00668Peer reviewe
Comparison of the Personality Profiles of Inmate Anonymous and Non-Anonymous Male Addicts
Aim: This study compared the personality profiles of inmate anonymous and non-anonymous male addicts. Method: The participants of study were anonymous and non-anonymous male addicts of the prisons of the Hamadan province in 1391. The population was 3130 addicts, including 627 anonymous and 2503 non-anonymous addicts. The 310 addicts were selected by stratified random sampling the sample size was determined by Cochran formula.The short-form NEO Five Factor personality questionnaire administered among selected sample. Data analyzed by descriptive statistic as frequency and percentage, also, inferential statistic as multivariate analysis of variance was run. Results: The results showed that personality profiles of anonymous and non-anonymous addicts were significantly different. That is, mean score of neuroticism in anonymous addicts was less than non anonymous. Also, mean score of extraversion was higher in anonymous addicts. Conclusion: It can be concluded that the anonymous male addicts are differ with non-anonymous male addicts in personality traits
Efficient force field calculation in articulated multiscale molecular simulations
Multiscale simulations of molecular systems such as proteins, DNAs, and RNAs
are implemented using models with different resolutions ranging from a fully atomistic model
to coarse-grained molecules, up to a continuum level system descriptions. For such simulations,
pairwise force calculation is a serious bottleneck which can impose a prohibitive amount
of computational load on the simulation if not performed wisely. Herein, a novel method is
presented to approximate the resultant force and the associated moment for long-range particlebody
and body-body interactions applicable to multiresolution coarse-grained simulation of
biopolymers. The resultant moment is due to the fact that the net force does not necessarily
act through the center of mass of the body. This moment is neglected in bead-based coarse
models which use particle dynamics to form the equations of motion of each large spherical
pseudo-atom. The presented method significantly reduces the cost of the force field calculations
specially in multiscale models which contain rigid subdomain