533 research outputs found
The causes of government and the consequences for growth and well-being
Using a large cross-country data set, the authors examine the factors that cause governments to grow, and analyze how the size of government affects growth, whether measured as income growth or other measures of well-being, such as infant mortality and life expectancy. They find no robust link between government size and per capita income. The factors they find to be important in explaining government size are relative prices, the age-dependency ratio, how long a country has been independent, relative political freedom, and openness in trade. Their results also partially support the view that governments use consumption to buffer external risk, especially in low-income countries. As for how government size affects growth, they find a robust and significant negative relationship between growth and government size, as measured by consumption. Policy distortions, predictably, also have a negative effect on growth. But the positive effects of well-functioning institutions and high quality in government bureaucracies can offset the negative influence of large government size alone. Finally, they find that social-sector spending can exert a positive influence by reducing infant mortality and raising life expectancy. Better income distribution, higher per capita income, higher per capita income growth, and more political freedom have the same positive effect on those two measures of well-being.Environmental Economics&Policies,Economic Theory&Research,National Governance,Payment Systems&Infrastructure,Knowledge Economy,Knowledge Economy,Environmental Economics&Policies,National Governance,Economic Theory&Research,Inequality
Wetting Behavior of Molten Ag Nanodroplet on the Cu Substrate
The main objective of this investigation was to study spreading of Silver (Ag) nanodroplet on the
Cooper (Cu) surface by molecular dynamics (MD) simulation method. The quantum Sutton-Chen (Q-SC)
many body potential was used to calculate cohesive energy as well as force experienced by every atoms.
The temperature and pressure of nanodroplet were controlled by Nose-Hoover thermostat and Berendsen
barostat respectively. The effect of nanodroplet size on the wetting and contact angle of silver nanodroplet
on a copper solid surface was calculated by changing the number of atoms within the nanodroplet. By varying
the cooling rate during spreading of nanodroplet, it was found that decreasing the cooling rate decreases
the contact angle of nanodroplet, and it spreads better on the copper surface. Also, increasing initial
temperature of nanodroplet decreased the contact angle.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3533
Comparison anti-giardia activity of Satureja hortensis alcoholic extract and metronidazole in vitro
Background and aims: Giardiasis is known as intestinal infection and created by the flagellate protozoan Giardia lamblia. Some studies showed that phenolic components, present in plant extracts and essential oils, have anti-Giardia activity. The current study was performed to compare anti-Giardia activity of Satureja hortensis (SH) alcoholic extract and metronidazole in vitro. Methods: In this Laboratory-experimental study, it was separated cysts from the feces by Bingham procedure with minor modification. The numbers of cysts were calculated with Hemusytumetr and the purified cysts of Giardia lamblia (500 µl) were exposed with 500 µl of extract at concentrations of 10, 100 and 200 mg/ml and 125 mg/kg of metronidazole for 30, 60 and 120 min. The numbers of dead and live cysts was enumerated with a microscope. Results: Findings in the currnt studyshowed an increase in anti-Giardia activity of extract at high concentrations with increasing time. SH, at 100 mg/ml killed 53 in 30 min, 68 in 60 min and 78 in 120 min. Also, the extract killed by 62 in 30 min, about 88 in 60 minutes and 92 in 120 minutes. The drug had similar effects in 60 and 120 minutes, but it killed 83 in 30 minutes. Conclusion: SH alcoholic extract showed anti-Giardia activity at high rates and more time. Thus, SH extract at 200 mg may be suitable alternative for Metronidazole, without side effects. However, anti-Giardia activity of SH needs to more attentions, especially clinical investigations
Convex hull ranking algorithm for multi-objective evolutionary algorithms
AbstractDue to many applications of multi-objective evolutionary algorithms in real world optimization problems, several studies have been done to improve these algorithms in recent years. Since most multi-objective evolutionary algorithms are based on the non-dominated principle, and their complexity depends on finding non-dominated fronts, this paper introduces a new method for ranking the solutions of an evolutionary algorithm’s population. First, we investigate the relation between the convex hull and non-dominated solutions, and discuss the complexity time of the convex hull and non-dominated sorting problems. Then, we use convex hull concepts to present a new ranking procedure for multi-objective evolutionary algorithms. The proposed algorithm is very suitable for convex multi-objective optimization problems. Finally, we apply this method as an alternative ranking procedure to NSGA-II for non-dominated comparisons, and test it using some benchmark problems
Creeping thermocapillary motion of a Newtonian droplet suspended in a viscoelastic fluid
In this work we consider theoretically the problem of a Newtonian droplet
moving in an otherwise quiescent infinite viscoelastic fluid under the
influence of an externally applied temperature gradient. The outer fluid is
modelled by the Oldroyd-B equation, and the problem is solved for small
Weissenberg and Capillary numbers in terms of a double perturbation expansion.
We assume microgravity conditions and neglect the convective transport of
energy and momentum. We derive expressions for the droplet migration speed and
its shape in terms of the properties of both fluids. In the absence of shape
deformation, the droplet speed decreases monotonically for sufficiently viscous
inner fluids, while for fluids with a smaller inner-to-outer viscosity ratio,
the droplet speed first increases and then decreases as a function of the
Weissenberg number. For small but finite values of the Capillary number, the
droplet speed behaves monotonically as a function of the applied temperature
gradient for a fixed ratio of the Capillary and Weissenberg numbers. We
demonstrate that this behaviour is related to the polymeric stresses deforming
the droplet in the direction of its migration, while the associated changes in
its speed are Newtonian in nature, being related to a change in the droplet's
hydrodynamic resistance and its internal temperature distribution. When
compared to the results of numerical simulations, our theory exhibits a good
predictive power for sufficiently small values of the Capillary and Weissenberg
numbers.Comment: 18 pages, 7 figures, submitted to J. Fluid Mec
On the similarities of the sPTT and FENE-P models for polymeric fluids
For many commonly used single mode viscoelastic constitutive equations of differential type, it is well known that they share many features. For example, in certain parameter limits the models due to Giesekus, Phan-Thien Tanner and FENE-type models approach the Oldroyd-B model. In this talk, I'll compare the response of the linear form of the simplified Phan-Thien Tanner model [due to Phan-Thien and Tanner, Journal of Non-Newtonian Fluid Mechanics, 2 (1977) 353–365] (the "sPTT") and the Finitely Extensible Nonlinear Elastic model that follows the Peterlin approximation [due to Bird et al., Journal of Non-Newtonian Fluid Mechanics, 7 (1980) 213–235] (the "FENE-P"). I'll show that for steady homogeneous flows such as steady simple shear flow or pure extension the response of both models is identical under certain conditions. For more general flows we show analytically that the results from the two models only formally approach each other when both the polymer concentration and Weissenberg number is small. We then use a numerical approach to investigate the response of the two models when the flow is "complex" under two different definitions: firstly, when the applied deformation field is homogenous in space but transient in time (so called "start-up" shear and planar extensional flow) and then for "complex" flows (through a range of geometries) which, although Eulerian steady, are unsteady in a Lagrangian sense. Under the limit that the flows remain Eulerian steady (so the Weissenberg number is typically small), we see once again a very close agreement between the FENE-P and sPTT models
Characterization of a Wireless Vacuum Sensor Prototype Based on the SAW-Pirani Principle
A prototype of a wireless vacuum microsensor combining the Pirani principle and surface acoustic waves (SAW) with extended range and sensitivity was designed, modelled, manufactured and characterised under different conditions. The main components of the prototype are a sensing SAW chip, a heating coil and an interrogation antenna. All the components were assembled on a 15 mm × 11 mm × 3 mm printed circuit board (PCB). The behaviour of the PCB was characterised under ambient conditions and in vacuum. The quality of the SAW interrogation signal, the frequency shift and the received current of the coil were measured for different configurations. Pressures between 0.9 and 100,000 Pa were detected with sensitivities between 2.8 GHz/Pa at 0.9 Pa and 1 Hz/Pa close to atmospheric pressure. This experiment allowed us to determine the optimal operating conditions of the sensor and the integration conditions inside a vacuum chamber in addition to obtaining a pressure-dependent signal
Recycled cobalt from spent Li-ion batteries as a superhydrophobic coating for corrosion protection of plain carbon steel
A new recycling and film formation scheme is developed for spent Li-ion batteries, which involves the combination of ascorbic-assisted sulfuric leaching and electrodeposition to fabricate a corrosion resistance superhydrophobic coating. The idea behind the simultaneous use of sulfuric and ascorbic is to benefit from the double effect of ascorbic acid, as a leaching reducing agent and as morphological modifier during electrodeposition. Quantum chemical calculations based on the density functional theory are performed to explain the cobalt-ascorbate complexation during the electrocristalization. The optimum parameters for the leaching step are directly utilized in the preparation of an electrolyte for the electrodeposition process, to fabricate a superhydrophobic film with a contact angle of > 150\ub0 on plain carbon steel. The potentiodynamic polarization measurments in 3.5 wt % NaCl showed that boric-pulsed electrodeposited cobalt film has 20-times lower corrosion current density and higher corrosion potential than those on the non-coated substrate
A computational framework for modeling cell-matrix interactions in soft biological tissues
Living soft tissues appear to promote the development and maintenance of a
preferred mechanical state within a defined tolerance around a so-called
set-point. This phenomenon is often referred to as mechanical homeostasis. In
contradiction to the prominent role of mechanical homeostasis in various
(patho)physiological processes, its underlying micromechanical mechanisms
acting on the level of individual cells and fibers remain poorly understood,
especially, how these mechanisms on the microscale lead to what we
macroscopically call mechanical homeostasis. Here, we present a novel finite
element based computational framework that is constructed bottom up, that is,
it models key mechanobiological mechanisms such as actin cytoskeleton
contraction and molecular clutch behavior of individual cells interacting with
a reconstructed three-dimensional extracellular fiber matrix. The framework
reproduces many experimental observations regarding mechanical homeostasis on
short time scales (hours), in which the deposition and degradation of
extracellular matrix can largely be neglected. This model can serve as a
systematic tool for future in silico studies of the origin of the numerous
still unexplained experimental observations about mechanical homeostasis
Mid-Infrared Spectroscopy of Optically Faint Extragalactic 70 micron Sources
We present mid-infrared spectra of sixteen optically faint sources with 70
micron fluxes in the range 19-38mJy. The sample spans a redshift range of
0.35<z<1.9, with most lying between 0.8<z<1.6, and has infrared luminosities of
10^{12} - 10^{13} solar luminosities. Ten of 16 objects show prominent
polycyclic aromatic hydrocarbon (PAH) emission features; four of 16 show weak
PAHs and strong silicate absorption, and two objects have no discernable
spectral features. Compared to samples with 24 micron fluxes >10mJy, the 70\um
sample has steeper IR continua and higher luminosities. The PAH dominated
sources are among the brightest starbursts seen at any redshift, and reside in
a redshift range where other selection methods turn up relatively few sources.
The absorbed sources are at higher redshifts and have higher luminosities than
the PAH dominated sources, and may show weaker luminosity evolution. We
conclude that a 70 micron selection extending to ~20mJy, in combination with
selections at mid-IR and far-IR wavelengths, is necessary to obtain a complete
picture of the evolution of IR-luminous galaxies over 0<z<2.Comment: ApJ accepte
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