33,834 research outputs found
Owning your own home: reality or myth
The focus of the white paper will be to highlight the housing challenges that people in the New England region and in the United States face. Affordability, sustainability, people needs, societal needs, environmental needs, economic incentives and impact of government policies are just a few of the topics that will be explored
A model for hierarchical patterns under mechanical stresses
We present a model for mechanically-induced pattern formation in growing
biological tissues and discuss its application to the development of leaf
venation networks. Drawing an analogy with phase transitions in solids, we use
a phase field method to describe the transition between two states of the
tissue, e.g. the differentiation of leaf veins, and consider a layered system
where mechanical stresses are generated by differential growth. We present
analytical and numerical results for one-dimensional systems, showing that a
combination of growth and irreversibility gives rise to hierarchical patterns.
Two-dimensional simulations suggest that such a mechanism could account for the
hierarchical, reticulate structure of leaf venation networks, yet point to the
need for a more detailed treatment of the coupling between growth and
mechanical stresses.Comment: To appear in Philosophical Magazine. 18 pages, 8 figure
Self-induced balloon motions and their effects on wind data
Self-induced balloon motions and effects on wind measurement
Invariant Regions and Global Asymptotic Stability in an Isothermal Catalyst
A well-known model for the evolution of the (space-dependent) concentration and (lumped) temperature in a porous catalyst is considered. A sequence of invariant regions of the phase space is given, which converges to a globally asymptotically stable region . Quantitative sufficient conditions are obtained for (the region to consist of only one point and) the problem to have a (unique) globally asymptotically stable steady state
Dynamics of conduction blocks in a model of paced cardiac tissue
We study numerically the dynamics of conduction blocks using a detailed
electrophysiological model. We find that this dynamics depends critically on
the size of the paced region. Small pacing regions lead to stationary
conduction blocks while larger pacing regions can lead to conduction blocks
that travel periodically towards the pacing region. We show that this
size-dependence dynamics can lead to a novel arrhythmogenic mechanism.
Furthermore, we show that the essential phenomena can be captured in a much
simpler coupled-map model.Comment: 8 pages 6 figure
XMM-Newton and Gemini Observations of Eight RASSCALS Galaxy Groups
We study the distribution of gas pressure and entropy in eight groups of
galaxies belonging to the ROSAT All-Sky Survey / Center for Astrophysics Loose
Systems (RASSCALS). We use archival and proprietary XMM-Newton observations,
supplementing the X-ray data with redshifts derived from the literature; we
also list 127 new redshifts measured with the Gemini North telescope. The
groups show remarkable self-similarity in their azimuthally averaged entropy
and temperature profiles. The entropy increases with radius; the behavior of
the entropy profiles is consistent with an increasing broken power law with
inner and outer slope 0.92+0.04-0.05 and 0.42+0.05-0.04 (68% confidence),
respectively. There is no evidence of a central, isentropic core, and the
entropy distribution in most of the groups is flatter at large radii than in
the inner region, challenging earlier reports as well as theoretical models
predicting large isentropic cores or asymptotic slopes of 1.1 at large radii.
The pressure profiles are consistent with a self-similar decreasing broken
power law in radius; the inner and outer slopes are -0.78+0.04-0.03 and
-1.7+0.1-0.3, respectively. The results suggest that the larger scatter in the
entropy distribution reflects the varied gasdynamical histories of the groups;
the regularity and self-similarity of the pressure profiles is a sign of a
similarity in the underlying dark matter distributions.Comment: Accepted for publication in the Astrophysical Journa
Fatigue of intermittently stimulated quadriceps during imposed cyclical lower leg movements
During prolonged experiments the influence of knee angular velocity, and stimulation parameters (interpulse interval (IPI), duty cycle (DC), number of pulses per cycle (NP)) on fatigue-induced torque\ud
decline of paralyzed human quadriceps was studied. Identification of torque-angle and -angular velocity was also performed. The overall loss of maximum torque (MT) and torque-time integral ('lTI) per cycle during sustained intermittent stimulation during isokinetic movement had a typical exponential decay reaching asymptotic values. Larger knee velocities resulted in a significantly faster and relative larger decay of MT and TTI. The rate and relative magnitude of fatigue during concentric contractions are in direct relation\ud
to NP. The results may be valuable in the design of optimal control systems for FES which pursue minimization of muscle fatigue
Analisis Business Model Canvas Pada CV. Triputra Perkasa
Penelitian ini bertujuan untuk menganalisis dan merumuskan pengembangan model bisnis yang dimiliki CV. Triputra Perkasa dengan menggunakan business model canvas sebagai alat untuk mengindentifikasi. Jenis penelitian yang digunakan adalah penelitian kualitatif deskriptif. Sumber data yang digunakan adalah data primer berupa wawancara kepada 5 orang narasumber yaitu pemilik, project manager, kepala administrasi dan keuangan, rekan kerja dan pelanggan serta data sekunder berupa company profile. Hasil yang didapat berupa gambar 9 elemen pada current model canvas dan Perumusan pengembangan berupa gambar 9 elemen future model canvas
- …